Helicarionid snails of Mounts Mahermana, Ilapiry, and Vasiha, southeastern Madagascar

30 Pages·2000·13.2 MB·

THE VELIGER
© CMS, Inc., 2000
The Veliger43(3):218-247 (July 3, 2000)
Helicarionid Snails of Mounts Mahermana, Ilapiry, and Vasiha,
Southeastern Madagascar
KENNETH EMBERTON
C.
Florida Museum of Natural History, Box 117800, Gainesville, Florida 32611-7800, USA
AND
TIMOTHY A. PEARCE'
Delaware Museum ofNatural History, Box 3937, Wilmington, Delaware 19807-0937, USA
Abstract. Quantitative, replicated altitudinal transects yielded 30 helicarionid species in five genera in four subfam-
ilies. Descriptions are given of Kalidos balstoni (Angas, 1877); K. fenni sp. nov.; K. prenanti Fischer-Piette, Blanc,
&
Blanc Salvat, 1994; K. richardi sp. nov.; K. striaspiralis sp. nov.; K. vasihae sp. nov.; K. zahamenensis Fischer-Piette,
Blanc, Blanc & Salvat, 1994; Kaliella barrakporensis (Pfeiffer, 1852); Malagarion tillieri sp. nov.; Microcystis andria-
mahajai sp. nov.; Mic. basampla sp. nov.; Mic. blanci sp. nov.; Mic. castanea sp. nov.; Mic. compacta sp. nov.; Mic.
esetra sp. nov.; Mic. ilapiriensis sp. nov.; Mic. mahermanae sp. nov.; Mic. subangulata sp. nov.; Mic. subplanata sp.
nov.; Mic. vohimenae sp. nov.; Mic. vohimenoides sp. nov.; Sitala aliceae sp. nov.; S. amabilis Fischer-Piette & Salvat,
1966; S. elegans sp. nov.; S. euconuliforma sp. nov.; S. gaudens Fischer-Piette & Salvat, 1966; 5. ilapiryae sp. nov.;
S.josephinae sp. nov.; S. soa sp. nov.; and S. vasihae sp. nov.
INTRODUCTION MBI 374 (= Tol-2). Slope of Mt. Mahermana, 300 m,
24°26'17"S, 47°13'10"E.
This paper is the final in a series offour that identify and MBI 375 (= Tol-3). Slope of Mt. Mahermana, 200 m,
describe the species reported on as morphospecies by 24°26'I5"S, 47°13'04"E.
Emberton et al. (1996, 1999) and Emberton (1997). This MBI 376 (= Tol-4). Valley on Mt. Mahermana, 100
paper treats the Mahermana-Ilapiry-Vasiha helicarionids. m, 24°26'22"S, 47°12'41"E.
MBI 377 (= Tol-5). Sunmiit of Mt. Ilipiry, 540 m,
MATERIALS and METHODS 24°5r40"S, 47°00'20"E.
MBI 378 (= Tol-6). Ridge on Mt. Ilipiry, 500 m,
Collecting methods have been detailed by Emberton et 24°51'33"S, 47°00'27"E.
al. (1996). Sixteen stations were collected and numbered MBI 379 (= Tol-7). Ridge, valley, and slope on Mt.
in the "Tol" series (for Tolagnaro = Fort Dauphin, the Ilipiry, 400 m, 24°5r27"S, 47°00'38"E.
nearest city). These stations have been mapped by Em- MBI 380 (= Tol-8). Slope of Mt. Ilipiry, 300 m,
berton et al. (1996, 1999) and in Emberton (1997). To 24°51'36"S, 47°00'40"E.
shorten the taxonomic descriptions, stations are described MBI 381 (= Tol-9). Slope of Mt. Ilipiry, 200 m,
briefly below. Catalogued station numbers, given in pa- 24°51'39"S, 47°00'46"E.
rentheses, are in the series of the Molluscan Biodiversity MBI 382 (= Tol-10). Lowersummit ofMt. Vasiha, 860
Institute (MBI). All stations were restricted to primary m, 24°55'18"S, 46°44'19"E.
forest that had no more than limited selective cutting. MBI 383 (= Tol-11). Slope of Mt. Vasiha, 700 m,
Ecological data are given by Emberton (1997:table 1). All 24°55'23"S, 46°44'27"E.
stations are in Madagascar: Tulear Province. Mount Mah- MBI 384 (= Tol-12). Slope of Mt. Vasiha, 500 m,
ermana (Vohimena Chain) is northeast of the village of 24°55'19"S, 46°44'45"E.
Esetra, Ilapiry (Vohimena Chain) is west ofMahialambo, MBI 385 (= Tol-13). Valley on Mt. Vasiha, 400 m,
and Vasiha (Anosy Chain) is west ofMalio. Latitude and 24°55'25"S, 46°44'45"E.
longitude are given in degrees, minutes, and seconds. MBI 386 (= Tol-14). Slope of Mt. Vasiha, 300 m,
MBI 373 (= Tol-1). Summit of Mt. Mahermana, 340 24°55'37"S, 46°44'49"E.
m, 24°26'12"S, 47°13'13"E. MBI 387 (= Tol-15). Slope of Mt. Vasiha, 200 m.
24°56'13"S, 46°45'13"E.
MBI 388 (= Tol-16). Slope of Mt. Vasiha, 100 m.
To whom reprint requests should be sent. 24°56'20"S, 46°46'07"E.
&
K. C. Emberton T. A. Pearce, 2000 Page 219
MBI 389 (= Tol-3-4). Incidental collecting between Representative: MBI 374.02DR, Tol-2 (ad).
TolM-B3Ian3d9T0ol(-4=. Tol-1-2). Incidental collecting between O(2thaed)r, sMpBeIci3m7e7n.s2:3AMB(I1 a3d7),3.M2BIID 3(719.ad3)1,DM(B2Iad3,726.j1uv9)D,
TsoulmM-m1BiItano3df9T1Motl.(-2=.IlTipoilr-ys,ubT-o5l-)5..Incidental collecting below M(1BaId,3719j.u3v1;AA(M1Sadc).,2M03B4I6138[01.a2d3]D),(MIBadI),38M2B.I243D81(.12a2dD,
MBI 392 (= Tol-7-9). Incidental collecting between 1 juv).
Tol-7 and Tol-9. Description of representative:
Species identifications and comparisons were made us- Shell Size and Shape. Diameter 3.0 mm; height 2.8
ing Fischer-Piette et al. (1994) and Emberton (1994). For mm. Height-diameter ratio 0.94. Whorls 5.4. Coiling
each species, the holotype or a representative shell was tightness (whorl number divided by natural logarithm of
photographed in apertural, apical, and basal views at shell diameter) 4.9. Spire angle 85 degrees. Shell slightly
6.4X, lOX, 16X, 25X, or 40X magnification, and in api- domed. Whorl periphery rounded to slightly angular, pre-
cal view at 40x magnification (Figures 1-39). Shell char- sutural ridge present. Suture depth one half whorl from
acters were measured, or measured and calculated, or aperture is 1.2% of shell diameter. Umbilicus 3% of shell
scored from the photographs or from the shells them- diameter. Shell color orange-brown.
selves. A shell-character matrix was prepared and used to Aperture. Aperture width (measured parallel to a line
code character-state data into the DELTA system (Dall- between the columellar and upper peristome insertions)
witz et al., 1993), which was then used to generate nat- 49% ofshell diameter. Aperture height-width ratio(height
ural-language species descriptions. measured to and perpendicular to a line between the col-
umellar and upper peristome insertions) 0.59. Distance
SYSTEMATICS
between the columellar and upper peristome insertions
Higher classification follows Ponder & Lindberg (1997), 81% of aperture width. Penultimate whorl projects into
Nordsieck (1986), and Vaught (1989). Type materials are body whorl, occupying 14% of aperture height measure.
placed in the United States National Museum, Washing- Lower peristome angle where it meets parietal wall (ap-
ton, D.C. (USNM); temporarily in the Molluscan Biodi- ertural view) 95 degrees.
versity Institute (MBI), whose collections will revert to Apex. First whorl diameter 0.4 mm. First two whorls
the Florida Museum of Natural History, Gainesville; and diameter 0.8 mm. Embryonic sculpture smooth.
in the Australian Museum, Sydney (AMS); the Museum Post-Embryonic Shell Sculpture. Post-embryonic shell
national d'Histoire naturelle, Paris (MNHN, which does with very fine, regularly spaced, crowded transverse
not assigncatalog numbers to its types); andtheAcademy lines.
ofNatural Sciences ofPhiladelphia (ANSP). Forparatype
localities, use the MBI catalog number to refer to the Variation: No conspicuous variation in size or shape.
station numbers (in parentheses) above. MBI catalog Distribution: Mts. Mahermana, Ilapiry, and Vasiha at
numbers consist of station number, period, species num- 100 to 860 m elevation (this paper), and India, Himalaya,
ber, D (dry) or A (alcohol-preserved), and when appro- Abyssinia, Commores, Mozambique, South Africa, and
priate H (holotype) or P (paratype) and/or R (represen- widespread on Madagascar (Fischer-Piette et al., 1994).
tative).
Family Helicarionidae: Subfamily
GASTROPODA
Class
Microcystinae
Clade HETEROBRANCHIA
Genus Microcystis Beck, 1837
PULMONATA
Clade
STYLOMMATOPHORA
Order Microcystis subplanata Emberton & Pearce, sp.
Suborder SIGMURETHRA
nov.
Infraorder HELICIDA
(Figures 1, 2, 3, 4)
Superfamily Helicarionoidea
Family Helicarionidae: Subfamily Sesarinae Microcystis sp. 01, Emberton et al., 1996:210. Emberton,
1997:1146, 1150.
Genus Kaliella Blanford, 1863
Holotype: USNM 860818 (ex MBI 373.09DH, Tol-1,
Kaliella barrakporensis (Pfeiffer, 1852) ad).
(Figure 39) Paratypes: MBI 373.09DP (2 ad, 7juv; AMS C. 203462
Kaliella sp. 01, Emberton et al., 1996:210. Emberton, 1997: [1 ad]; MNHN [1 ad]; ANSP 400840 [1 ad]), MBI
1147. 373.09AP (2 ad, 2 juv), MBI 374.19DP (1 ad, 1 juv).
Page 220 The Veliger, Vol. 43, No. 3
Figures 1-5
Figures 1-4. Microcystis subplanata Emberton & Pearce, sp. nov., holotype (Figure 1, four views) and paratypes
MBI 373.09DP (Figure 2, three views and spire), MBI 373.09DP (Figure 3, one view), and MBI 374.19DP(Figure
4, one view). Figure 5 (four views). Microcystis castanea Emberton & Pearce, sp. nov., holotype. All scale bars 1
mm.
K. C. Emberton & T. A. Pearce, 2000 Page 221
MBI 375.17DP (3 juv), MBI 375.17AP (2 juv), MBI Holotype: USNM 860819 (ex MBI 373.10DH, Tol-1,
390.03DP (1 juv). ad).
Type locality: Madagascar: Tulear Province: north of Paratypes: MBI 373.10DP (1 ad; AMS C.203463 [1 ad];
Fort Dauphin: northeast of village of Esetra: Summit of MNHN [1 ad]), MBI 374.20DP (1 ad), MBI 375.18DP
Mt. Mahermana, 340 m, 24°26'12"S, 47°13'13"E: primary (1 ad; ANSP 400841 [1 ad]).
rainforest.
Description of holotype: Type locality: Madagascar: Tulear Province: northwest
Shell Size and Shape. Diameter 7.0 mm; height 3.8 ofFort Dauphin: northeast ofvillage ofEsetra: southeast
mm. Height-diameter ratio 0.55. Whorls 4.5. Coiling slope of Mt. Vasiha, 700 m, 24°55'23"S, 46°44'27"E: pri-
tightness (whorl number divided by natural logarithm of mary rainforest.
shell diameter) 2.3. Spire angle 145 degrees. Shell not
domed. Whorl periphery rounded to slightly angular, no Description of holotype:
presutural ridge. Suture depth one half whorl from aper- Shell Size and Shape. Diameter 6.2 mm; height 3.8
ture is 0.7% of shell diameter. Sub-sutural line (where mm. Height-diameter ratio 0.61. Whorls 4.8. Coiling
inside ofshell wall meets previous whorl) visible through tightness (whorl number divided by natural logarithm of
translucent shell; width from suture to sub-sutural line shell diameter) 2.6. Spire angle 140 degrees. Shell slight-
(apical view) 1.1% of shell diameter. Umbilicus 0% of ly domed. Whorl periphery rounded to slightly angular,
shell diameter Shell color orange-brown. no presutural ridge. Suture depth one half whorl from
Aperture. Aperture width (measured parallel to a line aperture is 0.3% ofshell diameter Sub-suturalline (where
between the columellar and upper peristome insertions) inside ofshell wall meets previous whorl) visible through
47% ofshell diameter. Aperture height-widthratio (height translucent shell; width from suture to sub-sutural line
measured to and perpendicular to a line between the col- (apical view) 2.2% of shell diameter. Umbilicus 6% of
umellar and upper peristome insertions) 0.77. Distance shell diameter. Shell color red-brown.
between the columellar and upper peristome insertions Aperture. Aperture width (measured parallel to a line
85% of aperture width. Penultimate whorl projects into between the columellar and upper peristome insertions)
body whorl, occupying 32% of aperture height measure. 50% ofshell diameter Aperture height-widthratio(height
Lower peristome angle where it meets parietal wall (ap- measured to and perpendicular to a line between the col-
ertural view) 65 degrees. umellar and upper peristome insertions) 0.68. Distance
Apex. First whorl diameter 1.0 mm. First two whorls between the columellar and upper peristome insertions
diameter 1.8 mm. Embryonic sculpture smooth. 81% of aperture width. Penultimate whorl projects into
Post-Embryonic Shell Sculpture. Post-embryonic shell body whorl, occupying 29% of aperture height measure.
smooth with extremely fine incised spiral lines and weak,
irregular growth wrinkles, sculpture on shell base as on Lower peristome angle where it meets parietal wall (ap-
ertural view) 95 degrees.
upper parts of shell; incised lines extremely fine, more
Apex. First whorl diameter 1.1 mm. First two whorls
than 30 lines between sutures.
diameter 2.1 mm. Embryonic sculpture ofinterrupted spi-
Variation: The spire canbe almost entirely flat, andemp- ral ridges.
ty shells sometimes bleach white. The largest specimen Post-Embryonic Shell Sculpture. Post-embryonic shell
(stationMBI 373) is 8.2 mm in diameter, with4.2 whorls. smooth with extremely fine incised spiral lines and weak,
irregular growth wrinkles, sculpture on shell base as on
Comparisons: Shape similar to Microcystis platysma
upper parts of shell; about 15 fine incised lines between
Emberton, 1994, but two-thirds the diameter for slightly
more whorls and with a narrower aperture. At least 50% sutures.
larger for the same number &of whorls as M. argueyrolli Variation: The largest shell (station MBI 373) has a di-
Fischer-Piette, Blanc, Blanc Salvat, 1994.
ameter of 7.8 mm, with 4.8 whorls.
Distribution: Mt. Mahermana, 200-340 m elevation.
Comparisons: Fewerand more rapidly expanding whorls
Etymology: For its somewhat (L. sub-, under) flat (L. than Microcystis arnali Fischer-Piette, Blanc, Blanc &
plan-) shell shape. Salvat, 1994, which lacks the spiral grooves of this spe-
& cies and is light, not dark, in color
Microcystis castanea Emberton Pearce, sp. nov.
Distribution: Mt. Mahermana, 200-340 m elevation.
(Figure 5)
Microcystis sp. 02, Emberton et al., 1996:210. Emberton, Etymology: For its chestnut (L. castane-) shell color,
1997:1147, 1150. dark for the genus.
Page 222 The Veliger, Vol. 43, No. 3
&
Microcystis compacta Emberton Pearce, sp. shell coloration, but no conspicuous variation in size or
nov. shape.
(Figures 6, 7) Comparisons: Very similar to Microcystis amali Fi-
scher-Piette, Blanc, Blanc & Salvat, 1994, but conspicu-
Microcystis sp. 03, Emberton et al., 1996:210. Emberton. ously more elevated, with a squarer aperture, lacking any
1997:1146. 1150. trace of peripheral angulation, and with slightly looser
Holotype: USNM 860820 (ex MBI 378.04DH, Tol-6, coiling.
ad). Distribution: Mts. Mahermana, Ilapiry, and Vasiha, 100-
m
Paratypes: MBI 373.18DP (1 juv). MBI 373.18AP (3 860 elevation.
ad), MBI 374.2IDP (1 juv), MBI 375.23AP (1 juv), MBI Etymology: For its compact shape.
376.12DP (1 ad, 1 juv), MBI 376.12AP (1 ad), MBI
377.16DP (3 ad, 1 juv), MBI 377.16AP (1 juv), MBI Microcystis vohimenae Emberton & Pearce, sp.
378.04DP (2juv; AMS C.203464 [1 ad]; MNHN [1 ad]; nov.
ANSP 400842 [1 ad]), MBI 378.04AP (2 ad, 1 juv), MBI
379.24DP (1 ad, 4 juv), MBI 379.24AP (2 juv), MBI (Figure 8)
380.17DP (I ad, 1 juv), MBI 380.17AP (2 ad, 2 juv), Microcystis sp. 04, Emberton et al., 1996:209, 210. Ember-
MBI 381.17DP (2 juv), MBI 382.17DP (13 juv), MBI ton, 1997:1146, 1150.
382.17AP (2 ad, 2 juv), MBI 383.11DP (I ad), MBI Holotype: USNM 860821 (ex MBI 373.11DH, Tol-1,
384.15DP (1 juv), MBI 387.10DP (2juv), MBI 387.10AP
ad).
(1 juv), MBI 391.03DP (1 juv).
Paratypes: MBI 373.11DP (1 ad, 1 juv; AMS C.203465
Type locality: Madagascar: Tulear Province: north of [1 ad]; MNHN [1 ad]), MBI 373.11AP (1 ad, 1 juv), MBI
Fort Dauphin: west of village of Mahialambo: Ridge on 375.I9DP (1 juv), MBI 375.19AP (1 ad), MBI 376.24AP
east face of Mt. Ilapiry, 500 m, 24°51'3"S, 47°00'27"E: (1 ad), MBI 377.17DP (2 ad, 3 juv), MBI 377.17AP (1
primary rainforest. juv), MBI 378.24AP (1 ad, 1 juv).
Description of holotype: Type locality: Madagascar: Tulear Province: north of
Shell Size and Shape. Diameter 8.4 mm; height 5.9 Fort Dauphin: northeast of village of Esetra: Summit of
mm. Height-diameter ratio 0.71. Whorls 5.2. Coiling Mt. Mahermana, 340 m, 24°26'12'S,47°13'I3"E: primary
tightness (whorl number divided by natural logarithm of rainforest.
shell diameter) 2.4. Spire angle 125 degrees. Shell slight-
Description of holotype:
ly domed. Whorl periphery rounded to slightly angular, Shell Size and Shape. Diameter 2.2 mm; height 1.4
no presutural ridge. Suture depth one half whorl from
mm. Height-diameter ratio 0.66. Whorls 4.1. Coiling
aperture is 1.1% ofshell diameter. Sub-suturalline (where
tightness (whorl number divided by natural logarithm of
inside ofshell wall meets previous whorl) visible through
shell diameter) 5.2. Spire angle 130 degrees. Shell not
translucent shell; width from suture to sub-sutural line
(apical view) 0.7% of shell diameter Umbilicus 2% of domed. Whorl periphery rounded to slightly angular, no
presutural ridge. Suture depth one half whorl from aper-
shell diameter. Shell color orange-brown.
Aperture. Aperture width (measured parallel to a line ture is 0.2% of shell diameter Sub-sutural line (where
inside ofshell wall meets previous whorl) visible through
between the columellar and upper peristome insertions)
53% ofshell diameter. Aperture height-widthratio(height t(rapaincsallucevnitews)hel1l.;0%wiodfthshferllomdisaumteutreer.toUmsbuibl-iscutuusra1l%lionef
measured to and perpendicular to a line between the col-
shell diameter. Shell color orange-brown.
umellar and upper peristome insertions) 0.66. Distance
Aperture. Aperture width (measured parallel to a line
between the columellar and upper peristome insertions
85% of aperture width. Penultimate whorl projects into between the columellar and upper peristome insertions)
body whorl, occupying 30% of aperture height measure. 51% ofshell diameter Apertureheight-widthratio(height
Lower peristome angle where it meets parietal wall (ap- measured to and perpendicular to a line between the col-
umellar and upper peristome insertions) 0.71. Distance
ertural view) 80 degrees.
diaAmpeetxe.rFi1r.s3t mwmho.rlEmdbiramyeotneirc0.s7cumlpmt.ureFirosftwtewaokwhspoirrlasl b7beo6td%wyeoewfhnoartplhe,ertocucroceluupmwyieidltnlhag.r3Pa0en%nduloutfpipmaeapretretpuewrrheiosrhtleoimgpehrtojiemncesteasrstuiironent.so
ridges then also with weak growth wrinkles.
Post-Embryonic Shell Sculpture. Post-embryonic shell Lower peristome angle where it meets parietal wall (ap-
ertural view) 110 degrees.
smooth, no sculpture other than weak, irregularly spaced
Apex. First whorl diameter 0.4 mm. First two whorls
growth wrinkles.
diameter 0.7 mm. Embryonic sculpture smooth.
Variation: There is some slight variation in darkness of Post-Embryonic Shell Sculpture. Post-embryonic shell
&
K. C. Emberton T. A. Pearce, 2000 Page 223
Figures 6-8
Figures 6, 7. Microcystis compacta Emberton & Pearce, sp. nov., holotype (Figure 6) and paratype MBI 376.12DP
(Figure 7). Figure 8. Microcystis vohimenae Emberton & Pearce, sp. nov., holotype. All scale bars 1 mm.
Page 224 The Veliger, Vol. 43, No. 3
smooth, no sculpture other than weak, irregularly spaced Post-Embryonic Shell Sculpture. Post-embryonic shell
growth wrinkles. with very fine granulations. Shell base with fine incised
Variation: The largest specimen, from station MBI 373, spiral lines.
has a diameter of 2.4 mm, with 4.0 whorls. Comparisons: Most similar to Microcystis vohimenae
Comparisons: Similar in shape to but smaller and more sp. nov., but larger, with looser coiling, and with spiral
lines on the base.
tightly coiled than Microcystis ilapiriensis sp. nov., and
lacking its basal spiral-line sculpture. Similar in size and Distribution: Mt. Ilapiry, 400 m elevation.
coiling tightness toM. vohimenoides sp. nov., butwithout
its wide umbilicus, low aperture, and spiral-line sculpture. Etymology: For Mount Ilapiry, southern Vohimena
Chain.
Distribution: Vohimena chain (Mts. Mahermana and II-
apiry), 100 to 540 m elevation. Microcystis vohimenoides Emberton & Pearce, sp.
Etymology: For the Vohimena Mountain chain, north of nov.
Ft. Dauphin. (Figure 10)
&
Microcystis ilapiriensis Emberton Pearce, sp. Microcystis sp. 06, Emberton et al., 1996:210. Emberton,
nov. 1997:1148.
(Figure 9) Holotype: USNM 860823 (ex MBI 380.02DH, Tol-8,
ad).
Micro1c9y9s7t:i1s14s7p.. 05, Emberton et al., 1996:210. Emberton, Paratypes: MBI 380.02DP (0; AMS C.203467 [1 ad]),
Holotype: USNM 860822 (ex MBI 379.04DH, Tol-7, MBI 382.18DP (1 ad).
ad). Type locality: Madagascar: Tulear Province: north of
Paratypes: MBI 379.04DP (I juv; AMS C.203466 [1 oFofrtMtD.auIplhapiinr:y,we3s0t0omf,vi2l4l°ag5eI'o3f6"MSa,hi4a7l°a0m0b'4o0:"Es:outphrismlaorpye
ad]).
rainforest.
Type locality: Madagascar: Tulear Province: north of
Description of holotype:
Fort Dauphin: west ofvillage ofMahialambo: Ridge, val- Shell Size and Shape. Diameter 2.1 mm; height 1.2
ley, and slope on southsoutheast face of Mt. Ilapiry, 400 mm. Height-diameter ratio 0.59. Whorls 3.7. Coiling
m, 24°51'27"S, 47.00.38E: primary rainforest.
tightness (whorl number divided by natural logarithm of
Description of holotype: shell diameter) 5.0. Spire angle 140 degrees. Shell slight-
Shell Size and Shape. Diameter 3.5 mm; height 2.2 ly domed. Whorl periphery rounded to slightly angular,
mm. Height-diameter ratio 0.63. Whorls 4.8. Coiling no presutural ridge. Suture depth one half whorl from
tightness (whorl number divided by natural logarithm of aperture is 1.2% ofshell diameter Sub-sutural line (where
shell diameter) 3.8. Spire angle 125 degrees. Shell not inside ofshell wall meets previous whorl) visible through
domed. Whorl periphery rounded to slightly angular, no translucent shell; width from suture to sub-sutural line
presutural ridge. Suture depth one half whorl from aper- (apical view) 2.6% of shell diameter. Umbilicus 8% of
ture is 0.3% of shell diameter. Sub-sutural line (where shell diameter Shell color white.
inside ofshell wall meets previous whorl) visible through Aperture. Aperture width (measured parallel to a line
translucent shell; width from suture to sub-sutural line between the columellar and upper peristome insertions)
(apical view) 2.0% of shell diameter Umbilicus 4% of 50% ofshell diameter Aperture height-widthratio (height
shell diameter Shell color orange-brown. measured to and perpendicular to a line between the col-
Aperture. Aperture width (measured parallel to a line umellar and upper peristome insertions) 0.63. Distance
between the columellar and upper peristome insertions) between the columellar and upper peristome insertions
53% ofshell diameter. Aperture height-widthratio (height 75% of aperture width. Penultimate whorl projects into
measured to and perpendicular to a line between the col- body whorl, occupying 32% of aperture height measure.
umellar and upper peristome insertions) 0.61. Distance Lower peristome angle where it meets parietal wall (ap-
between the columellar and upper peristome insertions ertural view) 105 degrees.
79% of aperture width. Penultimate whorl projects into Apex. First whorl diameter 0.4 mm. First two whorls
body whorl, occupying 31% of aperture height measure. diameter 0.9 mm. Embryonic sculpture of weak spiral
Lower peristome angle where it meets parietal wall (ap- striae.
ertural view) 90 degrees. Post-Embryonic Shell Sculpture. Post-embryonic shell
Apex. First whorl diameter 0.6 mm. First two whorls smooth with extremely fine incised spiral lines and weak,
diameter 1.1 mm. Embryonic sculpture smooth. irregular growth wrinkles, sculpture on shell base as on
1
K. C. Emberton & T. A. Pearce, 2000 Page 225
Figures 9-1
Figure 9. Microcystis ilapiriensis Emberton & Pearce, sp. nov., holotype. Figure 10. Microcystis vohimenoides
Emberton & Pearce, sp. nov., holotype. Figure 11. Microcystis esetra Emberton & Pearce, sp. nov., holotype. All
scale bars 1 mm.
Page 226 The Veliger, Vol. 43, No. 3
upper parts of shell; about 10 fine incised lines between Microcystis andriamahajai Emberton & Pearce,
sutures. sp. nov.
Variation: No conspicuous variation in size or shape. (Figure 12)
Comparisons: Similar in its small size and extremely Microcystis sp. 08, Emberton et al., 1996:210. Emberton,
tight coiling to Microcystis vohimenae sp. nov., but with 1997:1148, 1150.
ascumlupctuhreloowfeirncaipseerdtusrpeiraalndliwneisd.er umbilicus, and with a Holotype: USNM 860825 (ex MBI 375.04DH, Tol-3, ad;
body preserved as MBI 375.04AH).
m
Distribution: Mts. Ilapiry and Mt. Vasiha, 300 to 860
elevation. P1ajruavt;ypAeMs:SMCB.I20337456.804[1DPad(]1;jMuvN),HMNBI[13a7d6])..13DP (2 ad,
Etymology: For its resemblance to M. vohimenae sp.
Type locality: Madagascar: Tulear Province: north of
nov.
Fort Dauphin: northeast of village of Esetra: west slope
Microcystis esetra Emberton & Pearce, sp. nov. of Mt. Mahermana, 200 m, 24°26'15"S, 47°13'04"E: pri-
mary rainforest.
(Figure 11)
Description of holotype:
Microcystis sp. 07, Emberton et al.. 1996:210. Emberton. Shell Size and Shape. Diameter 3.3 mm; height 2.3
1997:1148. mm. Height-diameter ratio 0.70. Whorls 4.8. Coiling
Holotype: USNM 860824 (ex MBI 375.03DH, Tol-3, ad; tightness (whorl number divided by natural logarithm of
body preserved as MBI 375.03AH). shell diameter) 4.0. Spire angle 125 degrees. Shell slight-
ly domed. Whorl periphery rounded to slightly angular,
Paratypes: None. no presutural ridge. Suture depth one half whorl from
Type Locality: Madagascar: Tulear Province: north of aperture is 1.1% ofshell diameter Sub-sutural line (where
inside ofshell wall meets previous whorl) visible through
Fort Dauphin: northeast of village of Esetra: west slope
of Mt. Mahermana, 200 m, 24°26'15"S, 47°13'04"E: pri- t(rapaincsallucevnitews)hel1l.;2%wiodfthshferllomdisaumteutreertoUmsbuibl-iscutuusra5l%lionef
mary rainforest.
shell diameter. Shell color orange-brown.
Description of holotype: Aperture. Aperture width (measured parallel to a line
Shell Size and Shape. Diameter 6.6 mm; height 3.9 between the columellar and upper peristome insertions)
mm. Height-diameter ratio 0.59. Whorls 4.2. Coiling 54% ofshell diameter Apertureheight-widthratio(height
tightness (whorl number divided by natural logarithm of measured to and perpendicular to a line between the col-
shell diameter) 2.2. Spire angle 150 degrees. Shell slight- umellar and upper peristome insertions) 0.60. Distance
ly domed. Whorl periphery rounded to slightly angular, between the columellar and upper peristome insertions
no presutural ridge. Suture depth one half whorl from 82% of aperture width. Penultimate whorl projects into
aperture is 0.9% ofshell diameter. Sub-suturalline (where body whorl, occupying 33% of aperture height measure.
inside ofshell wall meets previous whorl) visible through Lower peristome angle where it meets parietal wall (ap-
translucent shell; width from suture to sub-sutural line ertural view) 110 degrees.
(apical view) 1.9% of shell diameter. Umbilicus 5% of Apex. First whorl diameter 0.6 mm. First two whorls
shell diameter. Shell color orange-brown. diameter 1.1 mm. Embryonic sculpture smooth.
Apex. First whorl diameter 0.9 mm. First two whorls Post-Embryonic Shell Sculpture. Post-embryonic shell
diameter 1.9 mm. Embryonic sculpture smooth. smooth, no sculpture other than weak, irtegularly spaced
Post-Embryonic Shell Sculpture. Post-embryonic shell growth wrinkles.
smooth with extremely fine incised spiral lines and weak, Variation: No conspicuous variation in size or shape.
irregular growth wrinkles, sculpture on shell base as on
upper parts of shell; incised lines extremely fine, more Comparisons: Extremely similartoMicrocystissahavon-
than 30 lines between sutures. drononae Emberton, 1994, but even smaller and more
tightly coiled, with 4.8 whorls producing a diameter of
Comparisons: Like an enlarged version&of Microcystis 3.3 mm, whereas 4.5 whorls produce 3.7 mm in the latter
argueyrolli Fischer-Piette, Blanc, Blanc Salvat, 1994,
Also lacking the spiral sculpture ofM. sahavondrononae.
which it closely resembles in shapmemand, apparently, Much smaller and more tightly coiled than M. anosiana
sculpture, but witmhma diameter of6.6 for four whorls, Fischer-Piette, Blanc, Blanc & Salvat, 1994, and with a
as opposed to 5 for five whorls in M. argueyrolli.
straight columellar insertion (angled about 30 degrees in
Distribution: Mt. Mahermana, 200 m elevation. M. anosiana).
Etymology: For the village of Esetra. Distribution: Mt. Mahermana, 100 to 200 m elevation.
&
K. C. Emberton T. A. Pearce, 2000 Page 227
Figures 12 and 13
Figure 12. Microcystis andriatnahajai Emberton & Pearce, sp. nov., holotype. Figure 13. Microcystis blanci Em-
berton & Pearce, sp. nov., holotype. All scale bars 1 mm.
Etymology: For Dr Benjamin Andriamahaja, National Paratypes: MBI 380.03DP (0; AMS C.203469 [1 ad]),
Director of the Ranomafana National Park Project. MBI 380.03AP (4 ad, 1 juv).
Microcystis blanci Emberton & Pearce sp. nov. Type locality: Madagascar: Tulear Province: north of
Fort Dauphin: west ofvillage ofMahialambo: south slope
(Figure 13) of Mt. llapiry, 300 m, 24°51'36"S, 47°00'40"E: primary
rainforest.
Microcystis sp. 09, Emberton et al., 1996:210. Emberton,
1997:1148.
Description of holotype:
Holotype: USNM 860826 (ex MBl 380.03DH, Tol-8, ad Shell Size and Shape. Diameter 3.8 mm; height 2.4
shell; body included in MBI 380.03AP). mm. Height-diameter ratio 0.63. Whorls 3.4. Coiling