Notes on the non-marine molluscs of Borneo 10. The genera Bruggennea, Gulella and Sinoennea (Gastropoda, Pulmonata, Streptaxidae)

2007·0.69 MB·English

by  Vermeulen, J J

BASTERIA,71:169-176,2007
Notesonthe non-marinemolluscs of Borneo 10.ThegeneraBruggennea, Gulella
andSinoennea(Gastropoda, Pulmonata, Streptaxidae)
J.J. Vermeulen
NationaalHerbarium Nederland,Leiden Branch,P.O.Box 9514,
NL2300RALeiden,the Netherlands
Thespecies ofthegenera Bruggennea,GulellaandSinoennea (Streptaxidae)occurringinBorneo
are revised. Five species are dealt with, including Bruggennealuminifera spec. nov. and
Sinoennea kennethi spec. nov.
Key words: Gastropoda, Pulmonata,Streptaxidae,Bruggennea,Gulella,Sinoennea,taxonomy,
Malaysia,Borneo.
INTRODUCTION
OnBorneo, streptaxid molluscsdonotoccurinabundance,butcertainly theislandis
hometo asuite ofparticularly odd species. Thispaperpresents ashortrevision of the
generawith a more or less ellipsoid to cylindrical shell.For lenticular shells, like in
Platycochlium Laidlaw, 1950, see Vermeulen (1991). For species with a partly free last
whorl, likein Diaphera Albers, 1850, seeVermeulen(1990). This paperwouldhave com-
pleted the revision of Bornean streptaxids if not, meanwhile, another half-dozennew
Diaphera species hadbeenfoundin easternKalimantan.
For collections, the following abbreviations are used: NMW, National Museumof
Wales,Cardiff; RMNH, NationaalNatuurhistorischMuseumNaturalis,Leiden;V, Colin
J.J.Vermeulen,Leiden.
SYSTEMATICPART
Family Streptaxidae Gray, 1860
Keytothegenerain Borneo(characters apply toBorneanspecies only)
la.Shellwiderthanhigh,lenticular JPlatycochlium (see Vermeulen,1991)
lb.Shellhigher thanwide,(ob-)ovoid, ellipsoid or cylindrical 2
2a.Lastwhorlpartly free,notattachedtothespire JDiaphera (see Vermeulen,1990)
2b.Last whorlentirely attachedtothespire 3
3a.Whorls distinctlycrenellatedbelowthesuture Huttonella
3b.Whorlsnot crenellatedbelowthesuture 4
4a.Umbilicusopen;whorlswithvarices imperfectlyarranged intworows
onopposite sidesofthespire Bruggennea
4b.Umbilicusclosed;whorlswithvarices irregularly arranged aroundthespire
Sinoennea
170 BASTERIA, Vol. 71, No. 4-6,2007
Bruggennea Dance, 1972
Shell.- Shellslightly flattenedlaterally,apexslightly oblique. Whorlsattachedtoone
another downto the aperture,with3-4(-5) varices imperfectly arranged in tworows on
opposite sidesof the spire, with onerow approximately above the aperture. Sculpture
absent, orrestrictedto2-7deep, wellspacedradialgroovesabovetheaperture. Apertural
teeth onpalatal and basalsidewithoutindentationintheouter shell surface.Umbilicus
open,narrow.
Distribution.- Sarawak,endemic.Allthreespecies restricted tothe same limestone
hill in Sarawak:Tatau RiverBasin, BukitSarang.
Notes. - The only character unique to Bruggennea, when compared to Sinoennea
Kobelt, 1904,is theposition and thedistinctnessofthevarices.A lateralflattening occurs
in, for instance, S. irregularis (Moellendorff, 1900), from Vietnam, and S. malaccana
(Moellendorff 1902), from peninsular Malaysia. Thelatteralso haspatches of congested
radialribs onthespire whichare arranged asthevarices inBruggennea. Sinoenneaseems
to be a composite genus accommodating species with very different shells, and
Bruggennea may needre-delimitationwithinthiscontext. In fact, the characterset: 'shell
laterally flattened,varices arranged in tworows onopposite sidesof thespire', is shared
withPlatycochlium; perhaps its closestphylogenetic relativesare tobefoundthere.
Bruggennea isendemicto two small (total surface c. 0.3sqkm) limestonehillsinthe
TatauBasin, Sarawak. B. laidlawioccurs in largenumbers, butthe twootherspecies are
remarkably rare. Evenextensive samplinghas yielded only very fewspecimens.
Key tothespecies
la. Shell2.1-2.2 mm high.Whorlabovethe aperturesmooth Bi . bongi
lb.Shell3.4-4.2mm high.Whorl abovethe aperturewith2-7 deep,radialgrooves ... .2
2a. Shellellipsoid, atmostslightly (ob-)ovoid. Upper palatal toothdeep insidetheaper-
ture,short, notconnectedtothepalatal swelling in theperistome B.laidlawi
2b. Shell distinctly ovoid. Upper palatal tootha long lamella, connectedto the palatal
swelling in the peristome and almost touching the parietal lamellaover its entire
length B.luminifera
Bruggennea bongi (Dance, 1970)(fig. 1)
SinoenneabongiDance, 1970: 155;holotype("BukitSarang"),leg.Bong,NMW (notseen).
Bruggenneabongi(Dance, 1970);Dance, 1972:131.
Material seen.- Sarawak,2nc'div.: LowerTatauRiver valley, BukitSaranggroup (leg. Serena Lee,
V11852/1);do.,Bukit Anyi,NW.side (V 12980/1).
Shell.- Shellminute to verysmall, ovoid, with aroundedapex, very slightly lateral-
ly flattened,somewhattranslucentwhite,glossy. Whorls4 1/4-45/8, slightly convex, with
3-4lowto moderatelyhigh variceswhichareatmostslightlyconcave ontheanteriorside;
the uppermost varix at c. 2 1/2 whorl from the apex. Suture impressed. Protoconch
smooth. Teleoconch smooth. Umbilicus open, 0.2-0.3 mm wide; last whorl without
swelling on theumbilicaland basal side. Aperture oblong, with roundedlower edges.
Vermeulen: The generaBruggennea, GulellaandSinoenneaonBorneo 171
Peristomesimple, athick glazing ontheparietal side,withaslight notch inthe margin
over theparietalis, elsewhere distinctlyreflected, withaslight thickening to amoderate-
lydistinctknobonthepalatal side;abovethistheperistome recedes somewhat.Apertural
teeth: a prominent parietal lamella starting on the peristome and continuing deeply
inside;ashort,very inconspicuous palatal lamelladeep insidetheaperture,partly hidden
fromviewbehind theknobontheperistome, abasalknob deep insidetheaperture; acol-
umellarlamellastarting deep insideand continuing deeper inside. Height 2.1-2.2 mm;
width1.4-1.5 mm.Aperturalheight 0.8-0.85 mm,width 0.75-0.8mm.
Ecology. - Lowlandrainforestonlimestonebedrock.
Distribution.- Sarawak, 2nc' div.:TatauRiverBasin, BukitSarang. Endemic.
Notes.- Smallerthanthe other two species, and withoutradial groovesabove the
aperture.Itoccurs in very smallnumbers.Only twoshellswere foundamonghundreds
of.B. laidlawi.In fully adult shells thetwopalatal teethanteriortothelastvarix beforethe
apertureare notretained(oneobservation).
Bruggennea laidlawi (Dance, 1970)(fig.2)
Sinoennea laidlawi Dance,1970:154;holotype("BukitSarang"),leg.Bong,NMW (notseen,paratypesV
13260/5).
Bruggennealaidlawi (Dance,1970);Dance,1972:131.
Material seen.- Sarawak,2 div.:LowerTatau River valley, BukitSaranggroup (leg. M.Bong,V
13260/5,paratypes,seeabove;leg.Serena Lee,V 11850/>10);do.,BukitAnyi,NW.side (V12975/>10);do.,
BukitAnyi, SE.side(V 12976/>10);do.,BukitLebik, groundlevel (V12977/>10);do.,BukitLebik,sedi-
mentdepositsc.40mabovegroundlevel (V12978/>10).
Shell.- Shellverysmall,ellipsoid toslightly (ob-)ovoid,withabroadlyroundedapex,
somewhat laterally flattened, somewhattranslucent white, glossy. Whorls 4 1/8-5 1/2,
slightly convex, with4-5 distinct, highvarices whichare distinctlyconcave ontheanteri-
or side,in particular towards thebase of thewhorls; theuppermost varix at 1 5/8-2 1/8
whorl fromthe apex. Suture impressed. Protoconch smooth. Teleoconch smooth apart
from afewweak growth linesand 2-7deepradialgroovesimmediately abovetheaper-
ture.Umbilicusopen, 0.3-0.4mmwide;last whorlontheumbilicalandbasalsidewitha
slight swelling0.27-0.35mm fromtheperistome.Aperture slightly obliquelyoblong, with
roundededges. Peristomesimple, athickglazing ontheparietal side, withaslight notch
in themargin overtheparietalis, elsewheredistinctlyreflected, withaslightthickening to
a distinctknob onthe palatal side; abovethis theperistome recedes strongly. Apertural
teeth: a prominent parietal lamella starting on the peristome and continuing deeply
inside;ashort, inconspicuous palatal lamelladeep insidetheaperture,hiddenfromview
behind the knobonthe peristome, opposed to the parietal lamella; abasal knob deep
inside the aperture; a columellarlamellastarting deep inside and continuing deeper
inside.Height3.4-4.2mm;width2.1-2.4mm.Apertural height1.2-1.5mm,widthc. 1mm.
Ecology. -Lowlandrainforestonlimestonebedrock.
Distribution.- Sarawak, 2 div.:TatauRiverBasin, BukitSarang. Endemic.
Notes.- Adultanimalsalso develop asecondshellwall insidetheoriginal onein the
top whorls, apparently to reduce the living spaceinside the shell, aswas observed in
Diaphera moellendorffi(Hidalgo, 1889)andseveralotherspecies ofthatgenus(Fulton, 1907:
364), including theBornean.
Each varix on the spire indicates the position where a thickened peristome was
172 BASTERIA,Vol. 71, No.4-6, 2007
Figs1-3.Bruggenneaspecies. 1,B. bongi(Dance, 1970),Malaysia,Sarawak,BukitSarang.a,frontalview
(V 11852,shell height2.1 mm);b, umbilical view(V 12980,samemagnification).2, B. laidlawi (Dance,
1970),Malaysia,Sarawak,BukitSarang.a,frontalview(V12975,shellheight3.7mm);b, umbilical view;
c,frontalview(V 12975,shellheight4.2mm);d,frontalview,juvenileshell(V12975, shellheight2mm).
3, B. luminifera spec. nov., holotype, Malaysia, Sarawak, Bukit Sarang (V 12979, shell height 3.4
mm),a,frontalview;b, umbilical view.
Vermeulen:ThegeneraBruggennea, GulellaandSinoenneaon Borneo 173
Figs4-5.Gulella and Sinoennea species. 4,G.bicolor(Hutton,1834),Indonesia,Bali,Banyuputih(V4426,
shellheight5.5mm),frontal view. 5,S.kennethi spec. nov., holotype,Malaysia, Sarawak,GunungMulu
National Park (V5645,shellheight3.6mm).a,frontal view;b, umbilical view.
formedduring development. Juveniles atthestageofthelast varixbeforeadulthood(see
fig. 2d) havea more or less conical shell, obtusely angular atthe periphery, withand
obtusely triangular aperture whichis distinctly widerthanhigh.The dentitionisbasical-
ly identicalto thatinadult shells, buttheparietal lamellahasanoutwards curved crest,
and thecolumellarlamellais entirely hiddenbehind aconspicuous widening andthick-
ening of the peristome onthe columellarand basal side. In fully adult shellsthe two
palatal teethanteriorto thelast varixbeforetheaperture areusually persistent.
Bruggennea luminifera spec.nov.(fig. 3)
Material seen.- Sarawak,2 div.:LowerTatau River valley,Bukit Saranggroup (leg. SerenaLee,
V11851/2paratypes);do.,BukitAnyi,NW.side (V 12979/4paratypes, RMNH 109087/holotype).
Shell.- Shellvery small, ovoid, with aroundedapex, somewhat laterally flattened,
somewhat translucentwhite, glossy. Whorls4 1/8-5 1/2,top whorls moderately convex,
others slightly convex, with4 distinct, high varices which are distinctly concaveonthe
anteriorside, in particular towardsthebaseofthewhorls; theuppermostvarix at2 1/4-2
1/2whorlfromtheapex.Sutureimpressed.Protoconchsmooth.Teleoconchsmoothapart
froma fewweak growthlines and 5-7 deepradial groovesimmediately above the aper-
ture.Umbilicusopen,0.3-0.45 mmwide;lastwhorl ontheumbilicaland basalsidewith
a slightswelling c. 0.5mm from theperistome. Aperture slightly obliquely oblong, with
174 BASTERIA, Vol. 71, No. 4-6,2007
rounded edges. Peristome simple, athickglazing onthe parietal side,withaslight notch
inthemarginovertheparietalis,elsewhere distinctlyreflected,withadistinctknobonthe
palatal side;abovethistheperistome recedes strongly. Apertural teeth:aprominent, bul-
bous parietal lamella starting on the peristome and continuing deeply inside; a long
palatal lamellastarting attheknobontheperistome, opposed to theparietal lamellaso
that, overmostof itslength, thecrestsof thetwo almost touch;abasalknob deep inside
the aperture; a columellarlamellastarting deep insideand continuing deeper inside.
Height 3.4-3.6mm;width1.5-2.1mm. Aperturalheight 1.1-1.3mm,width1.0-1.1mm.
Ecology. - Lowlandrainforestonlimestonebedrock.
Distribution.- Sarawak,2 div.:TatauRiverBasin, BukitSarang. Endemic.
Notes. - DiffersfromB. laidlawiinhaving anovoid shell, andamuch longer palatal
lamellathatstarts attheperistome andover mostofitslengthalmosttouchestheparietal
lamellasoastoformabarrierseparating theangular corner fromtherest oftheaperture.
Like B. bongi,itonly occurs in smallnumbers.
GulellaPfeiffer, 1856
Shell. - Shellnot laterally flattened,apex not oblique. Whorlsattached toone anoth-
er downtotheaperture, withoutvarices. Sculpture: a crenellationbelowthesuture,radi-
al ribs neartheaperture. Apertural teeth onpalatal andbasal sidewitha deep indenta-
tionintheouter shellsurface.Umbilicusclosed, not coveredby theperistome.
Note.- The description applies toBorneanspecies only.
Gulellabicolor(Hutton, 1834)(fig.4)
Pupa bicolor Hutton, 1834: 86;holotype (India,"Mirzapur... atthe base ofthe walls ofmybungalow...
between Agraand Neemuch")(notseen).
Ennea bicolor (Hutton,1834);Issel, 1874:51.
Huttonella bicolor (Hutton,1834);Dance, 1970:153.
Material seen.- Sarawak, 1st div.:Penrissen valley, GunungSegu, roadside between bridgeand
KampongBunuk (V 11860/1).4thdiv.:Niah Caves National Park,S.sideoflimestone area,W.ofquarry
(DANIDA survey2003,reportloc. 8,V/10328/1).SABAH. InteriorProv.:Pinangahvalley, BatuUrun (V
1173/2).KudatProv.:BanggiIsland,S.end,beachdriftmaterial(V 1419/1);do.,Karakit Hill(V1452/>10;
V9468/2,V9481/4).Tawau Prov.:SegamaValley,hill NW.ofcrossingroad Sandakan-Lahad Datuwith
the SegamaRiver (V 1677/1);Sempomaarea, PulauBumbum nearSemporna(leg.G.W.H. Davison,V
11865/4);do.,PulauSelakannearSempoma(leg.G.W.H.Davison,V 11864/1).
Kalimantan. Kalimantan Timur:SangkulirangPeninsula,GuaAmpanasnearKampongPengadan
(leg.TNC Survey2004,V11862/9);do.,GuaMarduanearKampongPengadan(leg.TNC Survey2004,V
11863/6);nearSamarinda,KampongAir Putih (leg. TNC Survey2004,V 11861/4);do.,small limestone
outcrop between Bontang and Samarinda (leg. TNC Survey2004, V 12667/1). Kalimantan Selatan:
Meratus Mts.,W. flank,NatehnearBatuTangga,c.18km E. Barabai (V3037/2);do.,TelagaLangsat(V
3446/6);do.,BatuApoh(V3312/>10);Meratus Mts.,E. ofmountains,Batu TungganearSarungga,W.of
roadBatulicintoBenualawas (V272/>10).
Shell.- Shell(very) small, cylindrical butsomewhattaperingtowardstheapex, with
abroadlyroundedapex, somewhattranslucentwhite, glossy.Whorls6 1/8-73/8, slightly
convex, withoutvarices. Sutureimpressed. Protoconchsmooth. Teleoconchsmoothapart
Vertneulen:ThegeneraBruggennea, GulellaandSinoenneaonBorneo 175
from a distinct crenellationbelow the suture, which develops into low, rounded,well
spaced radialribsonthelastportionofthelastwhorl. Umbilicusclosed;lastwhorlwith-
out swelling ontheumbilicaland basal side. Aperture aboutrectangular with rounded
edges, withtwo distinct dentsin theouter surface, on thepalatal andbasal side, corre-
sponding withapertural teeth.Peristomesimple,athinglazing ontheparietalside,with-
outanotchin themargin over theparietalis, elsewherethickenedand somewhatreflect-
ed, only slightly receding onthe upperpalatal side. Apertural teeth: a prominent but
rathershort parietal lamellastarting onthe peristome; a distinct, more or less conical
palatal toothontheinner rim oftheperistome, abasalknobslightly deeper inslide;acol-
umellar lamellastarting closetotheperistome and continuing deeper inside. Height5.4-
7 mm;width1.3-1.7mm.Height aperture1.1-2.0mm,width 1.0-1.5mm.
Ecology. - Gardens,agricultural land,secondary woodland,alsoindry coastalareas.
Introduced,butnotobserved tobeinvasiveinprimary vegetation.
Distribution.- Borneo.Scatteredlocalities in Sarawak, Sabahand Kalimantan.Very
common; thelownumberofrecords reflectsacollecting biasagainstthehabitatpreferred
by the species. Naturalrangeuncertain;introduced,accidentally or deliberately (to con-
trolAchatinafulica),intothetropicsworldwide(Cowie, 1997:31).
SinoenneaKobelt, 1904
Shell.- Shellnot laterally flattened,apexnotoblique. Whorlsattachedtooneanoth-
er down to the aperture, with 3 varices about 2/3 whorl distant from one another.
Sculpture absent. Apertural teeth onpalatal and basal sidewithout indentationin the
outer shellsurface.Umbilicusclosed, coveredby theperistome.
Note.- The description appliestoBorneanspecies only. Theinclusionof S.kennethiis
doubtfulbutinspired by overallsimilarity withthe twospecies mentionedin thenotes
with its description. In fact, it occupies a position withinthegenus as marginal as the
species of Bruggennea, but Iprefer not to create yet another monotypic genuswithout
addressing thedelimitationof Sinoennea.
Sinoenneakennethispec.nov.(fig.5)
Material seen.- Sarawak, div.:GunungMulu National Park,Camp5(legSchuiteman,V5683/1
paratype, fragment); do., Sungei Melinau Paku headwaters, GunungApi (leg. Nilong, V 11414/1
paratype;leg.Schuiteman,V5444/1paratype,fragment;RMNH 109088/holotype).
Shell. - Shellvery small, ellipsoid-cylindrical, with abroadly rounded apex,white,
glossy. Whorlsc. 5, slightly convex, with3rather inconspicuous, low,rounded, varices,
theuppermost at c. 1 7/8 whorl from the apex. Suture impressed. Protoconchsmooth.
Teleoconchsmoothapartfromafewradialgroovesanteriortothelastvarixpreceding the
aperture.Umbilicusclosed; lastwhorl withoutswelling onthe umbilicaland basalside.
Aperturetriangular withroundededge anda concave columellarside.Peristomesimple,
athickglazing ontheparietal side,withoutanotchinthemargin over theparietalis, else-
where thickened andsomewhat reflected,with aknobonthepalatal side;abovethisthe
peristomerecedes strongly.Aperturalteeth:aprominent, thickparietallamellastartingon
theperistome andcontinuing deeplyinside;abasalknob deepinsidetheaperture;acol-
umellarlamellastarting deep inside and continuing deeper inside. Height c. 3.6 mm;
widthc.2mm. Apertural height c. 1.2mm, widthc. 1.3mm.
176 BASTERIA,Vol. 71, No. 4-6,2007
Ecology. - Forest onlimestonesoil. Foundat 150-1400 masl.
Distribution.- Sarawak, div.:Gunung MuluNationalPark.Endemic.
Notes.- Thecharacter set:'varices present, distinct; radial sculpture largely absent;
aperture triangular withaconcavecolumellar side' uniquely identify thisspecies within
Sinoennea.Sinoenneasplendens (Moellendorff, 1882), fromsouthernChina looks more or
lesssimilarbuthasaconvexcolumellarperistomewithtwolargeteethonthepalatalside.
Sinoenneaovulum (Bavay & Dautzenberg, 1912), from northernVietnam, differsin the
same characters but also in having distinct crenellationsbelow the suture. Sinoennea
austeni(Peile, 1929), fromIndia, seems tohavedistinct growth interruptions, or perhaps
smallvarices (indicated in the drawing, but notdescribed)in asimilarposition asS. ken-
nethi.It has no sculpture, but the aperture is more or less rectangular with a rounded
lowerside.
NamedafterMr.KennethNilong,whoundertookthesteepclimbtothepinnacle area
tocollectsoilsamples especially toobtainthisspecies.
ACKNOWLEDGEMENTS
Special thanks are due to Mr. S.P. Dance,who donatedtype materialof Bruggennea
laidlawi.Mr.KennethNilong, rangeratGunung MuluNationalPark, isrememberedwith
pleasure, inparticular hisability totreadlightlyandwitheaseonperilouslysteep slopes
with sharp limestoneoutcrops where the averagetourist, the author included, at best
stumblesignominously along infearforhishealthandworse.Inameacreature afterhim
thatmaybeassure-footedas he is, but definitelyslower.Thehospitality andsupportof
TheNationaal NatuurhistorischMuseum, Leiden (NNM) should, once more, be men-
tioned.Dr. A.C.vanBruggen was sokindto advise ontheposition of Sinoenneakennethi.
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