RECOGNITIONOF TWOSUBFAMILIESIN THEPOTAMIDAEORTMANN, 1896(BRACHYURA, POT AMIDAE)WITH ANOTE ON THE GENUS POTAMON SAVIGNY,1816

BY

DARREN C.J.YEO 1/ andPETER K.L.NG 2/ Rafes Museumof BiodiversityResearch, Department of Biological Sciences, NationalUniversity of Singapore,10 KentRidge Crescent, Singapore 119260, Rep. of Singapore

ABSTRACT Thefreshwater crab family Potamidae is classiŽ ed into two subfamilies based on differences inthestructure of the eighth thoracic sternite; one, the Potaminae, which is distributed in Europe, NorthAfrica, Socotra island (Y emen),the Near East, Middle East, northern India and Myanmar; andthe other, the Potamiscinae, which occurs in East and Southeast Asia. Their distributions are quitedistinct, overlapping only in northeastern India and Myanmar. The genus Potamon s. str. is, therefore,clearly absent from the fauna of EastAsia.

RÉSUMÉ

Lafamille de crabesd’ eau douce des Potamidae est classé e endeux sous-familles sur la basede différences portant sur la structure du huitiè me sternite thoracique; l’ une, les Potaminae, est ré partie enEurope, en Afrique du Nord,dans l’ île deSocotra(Y emen),le Proche-Orient,le Moyen-Orient, le nordde l’ Indeet le Myanmar;l’ autre, les Potamiscinae, se trouvent dans l’ estet le sud-estasiatique. Leursré partitions sont distinctes, ne serecouvrant que dans l’ Indenord-orientale et le Myanmar. Le genre Potamon s.str. est donc clairement absent de la faunede l’Asieorientale.

INTRODUCTION Thefreshwater crabfamily Potamidae Ortmann,1896, is alarge,diverse group with some 500species in 74genera, with amoreor less continuousAfro-Eurasian distribution, rangingfrom South Europe and North Africa, and across to East and Southeast Asia. Theyare, however, absent frommost ofthe Indiansubcontinent, beingpresent onlyin the northernpart (Bott, 1970b).One family, Potamidae,

1/ e-mail:[email protected] 2/ e-mail:[email protected] © KoninklijkeBrill NV ,Leiden,2004 Crustaceana 76(10):1219-1235 Alsoavailable online: www.brill.nl 1220 DARREN C.J.YEO&PETERK. L.NG is currentlyrecognized for all Asian potamoidcrabs (sensu Ng,1988; Ng & Naiyanetr,1993; Dai, 1999; Y eo& Ng,1999a), with Isolapotamidae Bott, 1970, andSinopotamidae Bott, 1970,as juniorsynonyms. Brandis (2002),however, recently revalidated the Isolapotamidae andSinopotamidae for selected Asian potamoidgenera, but the argumentspresented are notvery convincing and too fewtaxa weretreated (see below),with most ofthe generaunplaced. Withinthe Potamidae,Bott (1970b)had earlier recognizedtwo subfamilies on the basis ofdifferences inthe male Žrst pleopodstructure, viz.,the Potamiscinae [typegenus: Potamiscus Alcock,1909] and Potaminae [typegenus: Potamon Savigny,1816], but this was doubtedby Ng (1985, 1987), who consequently synonymizedthe twonames (see Ng,1988; Ng &Naiyanetr,1993). Observationsfrom the present study,however,show that the Potamidae (with Isolapotamidae andSinopotamidae as juniorsynonyms) can be dividedinto two distinct groups(but not in the sense ofBott, 1970b)on the basis ofdifferences in the structure ofthe eighththoracic sternite. Thesubfamily names,Potamiscinae andPotaminae, which remain available, are hereapplied to these twogroups. The present paperserves torevalidate andredeŽ ne the Potamiscinae andPotaminae basedon this keymorphological character. The two groups also haverelatively distinct distributions. Thetype genera for Potamiscinae andPotaminae, namely Potamiscus and Potamon,respectively,are currentlybeing rediagnosed and rede- Žned;and together with the present study,theyare part ofan ongoing revision ofthe taxonomyof the freshwater crabs [Potamidae andParathelphusidae] of Indochina(deŽ ned by political boundariesto includeCambodia, Laos, Vietnam, Thailand,and Myanmar) (D. C.J.Yeo,in prep.).

MATERIAL AND METHODS

Material examinedfrom Indochina and outside Indochina is listed inappen- dixI andappendix II, respectively; this consists ofnominal species fromboth Potamiscinae andPotaminae. Many specimens ofundescribedtaxa fromIndochina andother parts ofEast andSoutheast Asia werealso examined,and found to belongin the subfamily Potamiscinae as deŽned in this paper;these will be publishedin subsequentworks. The classiŽ cation usedin the appendiceses- sentially follows Naiyanetr(2001), Ng & Yeo(2001), Y eo& Naiyanetr(1999, 2000),Y eo& Ng(1999a,b), Y eoet al. (1999),and Brandis (2001).One genus, Paratelphusula ,hadbeen synonymized with Parapotamon byBott (1970),but is clearly agoodgenus (D. C.J.Yeo,unpubl. data). Brandis (2000,2002) syn- onymizedsome ofthe generaand species, butwe disagree as this was basedal- most completely onthe formof the male Žrst andsecond pleopods, and many RECOGNITION OFTWOSUBFAMILIES IN THEPOTAMIDAE 1221 othercharacters werenot considered. However, the genericplacements ofmany ofthe species listed inthe appendicesremain tentative, pendingrevision inan upcomingmonograph on the Indochinesefreshwater crabs (D.C. J. Yeo,in prep.). Specimens examinedfor this studyconsist oflarge series ofhistorical museum material andrecently collected material fromIndochina (see appendixI), includ- ingtypes ofmany nominal as well as undescribedtaxa (unpubl.data). Numer- ouspotamid taxa occurringoutside Indochina(Mediterranean region, Asia Mi- nor,South Asia, East Asia, andSoutheast Asia) werealso studied forcompara- tive purposes(see appendixII). For the sake ofbrevity, however, only the number ofspecimens andthe depositoryare shown.Moreover, for species dealt with in recent publications bythe authors,only the species nameis listed, andmaterial examinedhas beenleft out(see instead Naiyanetr,2001; Ng & Yeo,2001; Y eo &Naiyanetr,1999, 2000; Y eo& Ng,1999a, b; Yeoet al., 1999).The full list- ingof material examinedfor the studywill beincluded in anupcoming mono- graphon Indochinese freshwater crabs.The material is depositedin the follow- inginstitutions: Bernice P.BishopMuseum, Honolulu, Hawaii, U.S.A. (BPBM); ChulalongkornUniversity Natural History Museum,Bangkok, Thailand (CUMZ); Institute ofZoology, Chinese Academyof Sciences, Beijing, China(IZCAS); Naturhistorisches MuseumBasel, Basel, Switzerland (MBA); Museumof Com- parative Zoology,HarvardUniversity, Cambridge, Massachusetts, U.S.A.(MCZ); MuseoCivico di Storia Naturale “GiacomaDoria” , Genova,Italy (MGE);Musé um national d’Histoire naturelle, Paris, France(MNHN); Natural History Museum [formerlyBritish Museum(Natural History)],London, U.K. (NHM);Swedish Museumof Natural History,Stockholm, Sweden (NRM); National Science Mu- seum,T okyo,Japan (NSMT); Nationaal Natuurhistorisch Museum,Leiden, The Netherlands[formerly Rijksmuseum vanNatuurlijke Historie (RMNH)];Sencken- bergischenNaturforschenden Gesellschaft, Frankfurt,Germany (SMF); National Museumof Natural History,SmithsonianInstitution, Washington,D.C., U.S.A. (USNM);Zoö logisch MuseumAmsterdam, Amsterdam, The Netherlands(ZMA); ZoologicalMuseum of Hanoi University ,Hanoi,Vietnam (ZMHU);Zoologisk Museum,Copenhagen, Denmark (ZMUC); Zoological Reference Collection ofthe Rafes Museumof Biodiversity Research,National Universityof Singapore,Sin- gapore(ZRC); ZoologicalSurvey of India, Calcutta, India(ZSI); andZoologische Staatsammlung, Munich,Germany (ZSM). Theterminology used is explainedin Žg.1, and essentially follows Ng(1988). Measurements givenare ofcarapace width and length, respectively. All measure- ments are in millimetres (mm).The following abbreviations are used: G1 gono- D pod1 (male Žrst pleopod);G2 gonopod2 (male secondpleopod). D 1222 DARREN C.J.YEO&PETERK. L.NG

Fig.1. Terminologyused for posterior thoracic sternum.

SYSTEMATICS

Family POTAMIDAE Ortmann,1896 PotamonidaeOrtmann, 1896: 445 (part.); Rathbun, 1904: 244 (part.); Alcock, 1910: 16 (part.). Potamidae[correction of Potamonidae] – ICZN, 1964:336. Potamidae– Bott,1966: 470, 1967: 10, 1970a: 333, 339, 1970b: 134; Chuensri, 1973: 24, 1974a: 26,1974b: 1; Ng,1988: 28; Ng & Naiyanetr,1993: 6; Dai,1999: 85. SinopotamidaeBott, 1970a: 333, 1970b: 181; Brandis, 2002: 1300. IsolapotamidaeBott, 1970a: 333, 1970b: 190; Brandis, 2002: 1298.

Remarks.— Inthe present paper,we recognize only one family ,Potamidae, forall Europeanand Asian potamoidcrabs (sensu Ng,1988; Ng & Naiyanetr, 1993;Dai, 1999; Y eo& Ng,1999a). Brandis (2002)discussed the taxonomyof the Potamidae andconsidered the Isolapotamidae andSinopotamidae as separate families, onparwith the Potamidae.For the Isolapotamidae,he commentedthat it “: : : canonly be characterized consequentlyby a secondgonopod with avery narrowtube and a characteristic contact zone”(Brandis, 2002: 1300). He included in his Isolapotamidae just ŽveredeŽ ned genera, Isolapotamon , Nanhaipotamon , Dromothelphusa , Demanietta, and Flabellamon ,andone new genus, Takpotamon. Forthe Sinopotamidae,again, the onlycharacter is its detailed G2morphology,and henoted that its compositiondiffered from Bott’ s (1970a,b) concept. However, hedid not state whichgenera other than Sinopotamon wouldbelong in the Sinopotamidae.While the generalstructure ofthe G2is akeycharacter, which has beenused for several taxa offreshwater crabs at the genericlevel (Ng& Yeo, 1997),and the detailed structure maybe useful forhigher classiŽ cation, Brandis’ (2002)study ,unfortunately,treats toofew genera, and the degreeof variation in RECOGNITION OFTWOSUBFAMILIES IN THEPOTAMIDAE 1223 his G2character is notwell known.While weconcurthat his conclusionmay have akeyrole in the taxonomyand systematics ofAsian potamoidcrabs, most genera wereneither examinednor discussed, with their detailed G2condition (sensu Brandis,2002) not yet known.The familial afŽnities ofmost ofthe generawere notmentioned either .Inaddition, apart fromciting fourmorphological characters instructure andanatomy of G2 ofthe six genera,Brandis (2002)discussed little else that mightpossibly justify family level separation.Admittedly, Brandis (2002: 1300)notes that these families mayeventually be shown to bejust subfamilies within the Potamidae,but we feel that anoverreliance on G1 and G2 structures alonewill notsolve the problemsper se. Onthe otherhand, the structure ofthe thoracic sternum has beenshown to bevery valuable in elucidating brachyuran relationships, especially at the higherlevel (see Guinot,1977, 1979), and the observeddistributional patterns ofthe redeŽned Potaminae andPotamiscinae here also makemore biogeographical sense. Tothis effect, wehaveexamined 53 of the knowngenera, and utilized excellent drawingsof Dai (1999)for another 19. It is possible that Brandis’(2002) “ Sinopotamidae”and “ Isolapotamidae”are discrete monophyletictaxa, but they would then have to betribes withinthe Potamiscinae as deŽned, at present.

POTAMINAE Ortmann,1896 (Ž gs. 2A-D)

PotamoninaeOrtmann, 1896: 445 (part.); Rathbun, 1904: 274 (part.). Potaminae– Bott,1970b: 134 (part.);Chuensri, 1973: 25 (part.);1974a: 26 (part.); 1974b: 19 (part.).

Typegenus. — Potamon Savigny,1816, by original designation. Diagnosis.— Eighththoracic sternite incompletely separated bya longitudinal medianline, fusedanteriorly atthe suture betweensternites 7and8 bya narrow transverse ridgeinterrupting the longitudinalline. Remarks.— Bott (1970b)recognized two subfamilies withinthe freshwa- ter crabfamily ,Potamidae Ortmann,1896, viz., the Potamiscinae [typegenus: Potamiscus Alcock,1909] and Potaminae [typegenus: Potamon Savigny,1816], distinguished bywhether the groovefor the G2onthe G1terminal segment is visi- ble fromthe ventral side ornot. Ng (1985,1987), however, questioned the valueof Bott’s (1970b)character in separating Potamiscinae fromPotaminae, commenting that it was unreliable,and regarded them as synonyms(see also Ng,1988; Ng & Naiyanetr,1993). However,in the present study,six nominalpotamid genera ( Potamon Savigny, 1816; Paratelphusula Alcock,1909; Lobothelphusa Bouvier,1917; Acanthopota- mon Kemp, 1918; Himalayapotamon Pretzmann,1966; and Socotrapotamon Apel 1224 DARREN C.J.YEO&PETERK. L.NG

&Brandis,2000) (appendices I-B, II-B) werefound to share auniquemorpholog- ical character: the eighththoracic sternite is incompletely separated byalongitu- dinal medianline, beingfused anteriorly at the suture betweensternites 7and8 by anarrowtransverse ridgethat interrupts the longitudinalline (e.g.,Ž gs.1, 2A-D). Thelongitudinal median line is nota suture betweenthe left andright sides of the sternum butrather aninvagination of the sternum that correspondswith the positionof the vertical medianplate ofthe endophragmalskeleton (Guinot,1977; D.Guinot,pers. comm.), also knownas the medianseptum (Secretan,1998); and the description ofthe longitudinalmedian line as being“ interrupted”by atrans- verse ridgemerely refers toits appearancewhen viewed ventrally. The longitudi- nal medianline is, in fact, continuousand intact, with the transverse ridgeactually spanningover it. Oneundescribed species fromMyanmar and two species from India (Potamonlophocarpus Kemp,1913, and P.superciliosum Kemp,1913) also possess this character. Conversely, Potamiscus Bott, 1970,and all othernominal East andSoutheast Asian potamidtaxa examined(appendices I-A, II-A), consistently havethe eighth thoracic sternite completely separated bythe longitudinalmedian line, withno trace ofa transverse ridge(e.g., Ž gs.2E-H). This is also the case forthe rest of the Chinese potamidtaxa that werenot examined in the present study(see thoracic sternum illustrations in Dai,1999). Thetransverse ridgeon the eighththoracic sternite is averysigniŽ cant and consistent character (Žg. 2), and like otheraspects ofthe thoracic sternum ofcrabs, is notlikely to bein uenced by external environmentalfactors. Suchcharacters havebeen used to goodeffect in supragenericbrachyuran taxonomy (Guinot, 1977,1979). Therefore, on this evidence,two separate groupingsare recognized herewithin the Potamidae: oneconsisting of Potamon andallied genera,which havea transverse ridgeon the eighththoracic sternite, interruptingthe longitudinal medianline; andthe otherconsisting of Potamiscus andallied genera,which lack sucha ridge,and have an uninterrupted longitudinal median line. Thenames used byBott (1970b),Potaminae Ortmann,1896, and Potamiscinae Bott, 1970,are available andshould now be applied to these twogroups. It is important to note that the system usedhere in revivingthese names differs substantially fromBott’ s (1970b)system that was basedon the G1terminal segment (see above). Themorphologicaldifference between the twosubfamilies seems to bemirrored intheir distribution patterns, withPotaminae occurringin North Africa, on Socotra, andin western Eurasia; andPotamiscinae occurringin East andSoutheast Asia. Thedistributions ofboth groups overlap in Myanmar and northeastern India (Himalayas) (Žg. 3). Distribution. —SouthEurope, North Africa, Socotra, Near East, Middle East, andwestern India(Bott, 1970b;Brandis et al., 2000). RECOGNITION OFTWOSUBFAMILIES IN THEPOTAMIDAE 1225 , i ; e y i ) l n l b 8 a o a s 9 4 d m . a 4 n . 4 , a 0 5 M 5 - ( n 9 9 d n 9 e 9 l o a 1 1 a o s , C r m u W t , ( c R e ) s n i Z 5 ( a m 8 m y u ) 7 i a n t a 1 m a o , i N t P m n s , o b & 1 s r . E n e 9 g i ; ) 3 k H N t ( C a y n e R b l r i n t Z o o 6 ( k a . i m a ) 9 v a n 4 u t m ( n  o o m e p k l n a a a 9 o y . s a 4 m m . l n a 3 , a t A o 3 o y g m 2 n i P b n i 9 , e H 1 1 a . m A , , d 6 . p C m u 4 e ( ; a P m 0 ) . n e , e i 6 2 l c K 6 H ; a . s i ; 8 H m m ) - 9 m , u 7 9 a ) B n 3 t 1 7 a 4 n o . 9 i i P C 5 h 9 t , 9 1 i R m 9 H , Z m m - 1 ( e s E g 0 ) . C ; n u 5 s e m o R a o Z m m D n ( K i a s 2 t ) . m e o & l 3 a m P a t 3 g c o , m y F S P N 9 b ( . , ; . ) ) 7 6 D a 5 C . - 3 s . 1 R o 2 A . y 4 b Z . ( 9 b ( s b . i e b 9 ) 7 l g . a 0 a r m 2 9 a c 5 m l 1 m ( u d , i s 8 e 7 . l M u 6 m 6 a h a 9 H 3 t p m 1 l N o y , e , ( p t t b ) t ) a f 2 7 o r o 9 . m a B 8 9 P m m 1 4 e ( , u s , 8 r n . n t D r e 3 e e ; n t 2 n ) i s a t C y s y c i i e b R a c a Z l a 2 ( N . r a ( 0 o ) p 3 e h ( t m s n r n o m e e o l i m i a 0 r r a . t e u m 3 t o b s 3 e P a o p n y , p y a b f t B h o n ; 4 c ) . y s n s 5 e C a l 4 , k ( R p 9 Z 0 n e m ( l o 9 a a ) 1 x m m , m E o l k . , m e ) c 2 t 1 o . S 8 . 7 c g l , i 5 8 F 4 1 A G 1226 DARREN C.J.YEO&PETERK. L.NG . ) g n i h c t a h l a t n o z i r o h ( e a n i c s i m a t o P d n a ) g n i h c t a h l a n o g a i d ( e a n i m a t o P s e i l i m a f b u s e h t f o s n o i t u b i r t s i d e v i t a l e r g n i w o h s p a M . 3 . g i F RECOGNITION OFTWOSUBFAMILIES IN THEPOTAMIDAE 1227

POTAMISCINAE Bott, 1970 (Ž gs. 2E-H) PotamoninaeOrtmann, 1896: 445 (part.); Rathbun, 1904: 274 (part.). Potaminae– Bott,1970b: 134 (part.);Chuensri, 1973: 25 (part.);1974a: 26 (part.); 1974b: 19 (part.). PotamiscinaeBott, 1970b: 157; Chuensri, 1973: 28; 1974a: 28; 1974b: 19. SinopotamidaeBott, 1970a: 333; 1970b: 181; Brandis, 2002: 1300. IsolapotamidaeBott, 1970a: 333; 1970b: 190; Brandis, 2002: 1298.

Typegenus. — Potamiscus Alcock,1909, by original designation. Diagnosis.— Eighththoracic sternite withouttrace oftransverse ridgeat suture betweensternites 7and8, completely separated byuninterrupted longitudinal medianline in posterior sternum. Remarks.— Bott (1970b)originally deŽ ned the Potamiscinae basedon a G1 character (the groovefor the G2onthe G1terminal segment beingvisible fromthe ventral side) andlimited it to Indochineseand Malayan species; however,these G1 characters havebeen found to beuntenable (see earlier remarks forthe Potaminae, herein; Ng,1985,1987). Instead, the present deŽnition of the Potamiscinae is based onthe structure ofthe eighththoracic sternite (see above),and is nowexpanded to includeall East Asian andSoutheast Asian potamidspecies. This system differs fromBott’ s (1970a,b) substantially ,andall species previouslyclassiŽ ed in the Isolapotamidae andSinopotamidae (sensu Bott, 1970a,b; Brandis,2002) are here classiŽed in the subfamily Potamiscinae (see above).The differences betweenthe Potamiscinae andthe nominalpotamid subfamily ,the Potaminae Ortmann,1896, havebeen discussed abovein the remarks forPotaminae, herein. Distribution. —East andSoutheast Asia.

NOTE ON POTAMON SAVIGNY,1816 Thepresent revalidation andredeŽ nition of the subfamilies Potaminae and Potamiscinae has implications forthe taxonomyof Indochinese and Chinese potamidcrabs that needto bementionedhere. Bott (1970b)cited the distribution of Potamon (Potamon)as rangingfrom southernEurope, over the Himalayas, to Burma( Myanmar),and included D northeasternIndian (Himalayas), southernChinese, and Indochinese species. Inrecent years,numerous species fromIndochina and China that superŽcially resemble Potamon s. str.havebeen assigned to Potamon s. lato ona tentative basis, with the genusbeing used as a“catch-all”group, deŽ ned simply bythe presenceof adistinct third maxilliped exopod agellum (see also Naiyanetr& Ng, 1990;Ng &Naiyanetr,1993; Ng, 1996; Y eo& Ng,1997, 1998, 1999a; Dai, 1999). Manyof Wood-Mason’s (1871),Alcock’ s (1909,1910), and Kemp’ s (1913,1918b, 1228 DARREN C.J.YEO&PETERK. L.NG

1923a,b) species havealso beententatively retained in Potamon s. lato (see Yeo &Ng,1999a). The present study,however, shows that Potamon s. str. doesnot reachas far eastwards as the Himalayas, andis clearly absent fromthe faunaof Indochinaand China (present study; unpubl.data). Comparisonsof Indochinese as well as otherEast Asian (Himalayas and eastwards) taxa that resemble Potamon against members of Potamon s. str. ( D Potamon (Potamon)sensu Bott, 1967,1970b; Brandis et al., 2000)from the Mediterraneanand Middle East, showthat the latter groupdiffers fromall East Asian potamids most signiŽcantly bythe potaminecharacter ofthe eighththoracic sternite beingincompletely separated bya longitudinalmedian line, whichis anteriorly interrupted,just belowthe suture betweensternites 7and8, by a narrowtransverse sternal ridge(Ž gs. 1, 2A-D). East Asian potamids,on the other hand,belong to the subfamilyPotamiscinae (see Remarks forPotaminae and Potamiscinae) andhave a thoracic sternite 8that is completely separated byan uninterruptedlongitudinal median line, andlacks atransverse ridge(Ž gs. 2E-H). Potamon s. str., as deŽned above, occurs only as far east as the northwestern part ofIndia,corresponding with Alcock’s (1910:9) “ Western Frontier Territory”, fromwhich he reported only two Potamon species, P. (P.) uviatile ibericum (Bieberstein, 1809),and P. (P.) uviatile gedrosianum Alcock,1910, both of whichfall intothe present strict deŽnition of the genus(see Alcock,1910: 21, 23,Ž gs.1, 37; Bott, 1970b:138-139, pl. 37 Ž gs.7-10, pl. 43 Ž gs.8-9). No species of Potamon s. str. occurin northeasternIndia [Alcock’ s (1910:9) “ Western HimalayanTerritory” ]. Alcock(1910: 23) did report P. (P.) uviatile monticola Alcock,1910, from the “Western HimalayanTerritory” ; however,this species moreclosely resembles members of Himalayapotamon Pretzmann,1966 (see Annandale& Kemp,1913: pl. 14 Žg.5, 6); andAlcock (1910: 23) had also likened it to Himalayapotamonkoolooense (Rathbun,1904) (unpubl. data). Therefore, all Indochineseand Chinese species currentlyassigned to Potamon actually do notbelong to the genus.A similar conclusionwas independentlyreached by Brandis et al. (2000)based largely onG1 andG2 morphologyand anatomy. The genericplacements ofthe Indochinesespecies are beingrevised accordinglyin anupcoming monograph on the Indochinesefreshwater crabs,while the Chinese species will haveto bereappraisedin aseparate study.

ACKNOWLEDGEMENTS

DCJYis grateful to Danièle Guinotfor sharing her insight onbrachyuran sternal structure; andthe followingpersons for their generoushelp in facilitating access to museummaterial undertheir care: PhaibulNaiyanetr (CUMZ); Dai RECOGNITION OFTWOSUBFAMILIES IN THEPOTAMIDAE 1229

Aiyun(IZCAS); Giuliano Doria (MGE); Ambros Hä nggi (formerly of MBA); Ardis Johnston(MCZ); Danièle Guinot(MNHN); Paul Clark andMiranda Lowe (NHM);Charles Fransen(RMNH); Michael Türkay and Andreas Allspach (SMF); KarinSindemark (NRM); RaymondManning† and Karen Reed (USNM); Dirk Platvoet (ZMA);Nguyen Xuan Quynh (ZMHU); Danny Eibye-Jacobsen (ZMUC) andNiel Bruce(formerly of ZMUC);Y angChang Man and Y eoKeng Loo (ZRC); TusharenduRoy (ZSI); andLudwig Tiefenbacher (formerly of ZSM). Some fresh material was contributedby Louis Deharveng, Maurice Kottelat, Phaibul Naiyanetr,and Somsak Panha; as well as bymembers ofEcolab-NUS. This study was partly supportedby research grants to PKLNfromthe National University of Singapore.

APPENDIX I

Indochinesematerial examined

A. POTAMISCINAE (Thoracicsternite 8 with completelongitudinal median line, lacking transverseridge) . — Potamiscusrangoonensis (Rathbun, 1904): 2males(MBA 952a). Potamis- cusobliteratum Kemp, 1913 (ZSI 8147/10). Larnaudialarnaudii (A.Milne-Edwards, 1869): lectotype,male (MNHN-B 4357S);paralectotype: 1 female(MNHN-B 4357S). Larnaudiaadi- atretum (Alcock,1909): 1male,1 female(ZSI 6943/3);1 female(ZRC). Larnaudiabeuseko- mae (Bott,1970): holotype,male (RMNH D29312);paratypes: 2 females(RMNH D29313); others:2 males(ZRC 1985.4416-4417). Neolarnaudiabotti Türkay & Naiyanetr,1987: holo- type,male (MNHN-B 16933). Dromothelphusalongipes (A.Milne-Edwards, 1869): paralecto- type,female (MNHN-B 4037S);others: 2 females(MNHN-B 3827S),1 male,1 female(MNHN- B3828S);2 males,1 juvenilefemale (MNHN-B 17703),1 male,2 females(MNHN-B 17705); 1female(ZRC 1984.7034);1 female(MBA 908a);1 female(ZRC). Dromothelphusanamuan (Naiyanetr,1993): holotype,male (ZRC 1995.556). Dromothelphusanayung (Naiyanetr,1993): holotype,male (ZRC 1995.557);paratypes: 1 female(ZRC 1996.558),3 males,1 female(ZRC). Dromothelphusasangwan Naiyanetr,1997: holotype,male (RMNH D46774);paratypes: 1 fe- male(RMNH D46774),2 males,1 female(ZRC). Thaipotamonsphaeridium (Kemp,1923): holotype,juvenile female (ZSI C5901/1). Thaipotamonchulabhorn Naiyanetr,1993: holotype, male(RMNH D41613);paratypes: 1 female(RMNH D41614),1 male,1 female(ZRC 1995.559). Thaiphusatenasserimensis (DeMan, 1898): syntypes:2 males(MGE III272),1 female(MGE III271),1 female(MGE III270),1 male,1 female(ZMA De102.873.BR); others: 1 male,1 fe- male(ZRC 1965.12.7.99-100). Hainanpotamontankiense (Dang& Tran,1992): holotype,male (ZMHU); paratype:1 female(ZMHU). Hainanpotamonrubrum (Dang& Tran,1992): paratype, female(ZMHU). Potamonandersonianum (Wood-Mason,1871): topotype,male (SMF 2805); others:1 female(ZSI 6916/3);11 juveniles (ZSI 6932/3,6936/3);1 juvenilemale, 3 females(ZSI 6906/3);Holotype of Potamonandersonianum tritum Alcock,1909, female (ZSI 4075/4). Potamon edwardsi (Wood-Mason,1871): 1male,1 female(MGE III228bis); 1 male,2 females(MBA 51a);1 male(ZRC 1984.7036). Potamonhispidum (Wood-Mason,1871): 1juvenilefemale (ZSI 4007/4);1 female,1 juvenilemale (ZSI 7089-90/9). Potamoncochinchinense DeMan, 1898: lec- totype,female (ZMA De102.867.BR); other: 1 female(MNHN-B 5084). Potamonmooleyitense Rathbun, 1904: holotype,juvenile female (MGE III188). Potamonpaludosus Rathbun, 1904: holotype,female juvenile (MNHN-B 5264). Potamonbrousmichei Rathbun, 1904: lectotype,male 1230 DARREN C.J.YEO&PETERK. L.NG

(MNHN-B 5074);paralectotype: 1 female(MNHN-B 5074);other: 1 femalejuvenile (MNHN-B 5076). Potamonluangprabangense Rathbun, 1904: syntypes:1 male,1 female(MNHN-B 5225), 1female(MNHN-B 5224);others: 3 males,1 female(ZRC). Potamonpalustre Rathbun, 1904: holotype,male (MNHN-B 5265);others: 1 male(NRM). Potamonedwardsi hirtum Alcock,1909: holotype,female (ZSI 6961/3);others: 5 males,2 females(ZSI 6961/3). Potamonturgidulum Al- cock, 1909: syntype,female (NHM 1909.5.1.8). Potamonturgidulimanum Alcock,1910: syntype, juvenilemale (NHM 1909.9.2.2). Potamon (Potamiscus)aborense Kemp, 1913: syntypes:1 male (ZSI 8011/10),1 male,1 female(ZSI 8012-8013/10). Potamonfruhstorferi Balss,1914: holo- type,juvenile female (ZSM 1172/1). Potamonbrowneanum Kemp, 1918: topotype,male (NHM 1934.1.15.9)(formerly ZSI 9765/10);others: 2 males(ZSI 9764/10),1 juvenilemale, 3 juvenilefe- males(ZSI 9765/10);2 juvenilemales (ZSI 9766/10);1 female(ZSI 9767/10). Potamoncurtobates Kemp, 1918: topotype,male (ZSI 9776/10);other: 1 male(NRM 13920). Potamonphymatodes Kemp, 1923: syntypes:1 male,1 female(ZSI 592/1). Potamonklossianum Kemp, 1923: syntypes: 2males(ZSI C589/1);other: 1 female(ZRC 1989.2796). Potamonalcockianum Kemp, 1923: syn- types:3 juvenilemales (ZSI C597/1). Potamonsmithianum Kemp, 1923: holotype,female (ZSI 9627/10);others: 1 male(CUMZ); 10males, 7 females(ZRC 1990.498-514);5 males(RMNH D 29316);5 males,8 females,27 juveniles(ZRC); 1female(ZRC); 1juvenilefemale (ZRC); 1male, 1female(ZRC); 1female,3 subadultmales, 1 subadultfemale, 5 juveniles(ZRC); 2males,1 fe- male (ZRC). Potamonhafniense Bott, 1966: holotype,male (ZMUC Cru2532); paratypes: 5 juve- niles(ZMUC Cru2533), 2 males(SMF 2813);2 juveniles(ZMUC Cru2534); 1 juvenile(ZMUC Cru6651); others: 2 males,2 females(ZRC), 11males, 3 females(CUMZ). Potamonphuluan- gense (Bott,1970): holotype,male (RMNH D25141);paratypes: 2 males,1 female(SMF 4427), 5females(RMNH D25141A). Potamoncucphuongense (Dang,1975): 4males,1 female,6 ju- veniles(ZRC). Potamonkimboiense (Dang,1975): 1male,2 females(ZRC). Potamongalyaniae Naiyanetr,2001: holotype,male (CUMZ); paratypes:1 male,1 female(ZRC), 1female(CUMZ); 2females(CUMZ). Demaniettamanii (Rathbun, 1904) ¤. Demaniettarenongensis (Rathbun, 1905)¤. Demaniettathagatensis (Rathbun, 1904) ¤. Demaniettatritrungensis (Naiyanetr,1986) ¤. Demaniettahuahin Yeo,Naiyanetr & Ng,1999 ¤. Demaniettakhirikhan Yeo,Naiyanetr & Ng, 1999¤. Demaniettalansak Yeo,Naiyanetr & Ng,1999 ¤. Demaniettanakhonsi Yeo,Naiyanetr & Ng, 1999¤. Demaniettasuanphung Yeo,Naiyanetr & Ng,1999 ¤. Larnaudiachaiyaphumi Naiyanetr,1982 ¤. Tiwaripotamonaraneum (Rathbun, 1905) ¤. Tiwaripotamonsimulum (Alcock, 1909)¤. Tiwaripotamonannamense (Balss,1914) ¤. Tiwaripotamonedostilus Ng& Yeo,2001 ¤. Terrapotamonabbotti (Rathbun, 1898) ¤. Terrapotamonpalian Ng& Naiyanetr,1998 ¤. Phaibu- lamonstilipes Ng, 1992¤. Thaipotamonsiamense (A.Milne-Edwards, 1869) ¤. Thaipotamon lomkao Ng& Naiyanetr,1993 ¤. Thaipotamondansai Ng& Naiyanetr,1993 ¤. Thaipotamonva- roonphornae Ng& Naiyanetr,1993 ¤. Thaipotamonkittikooni Yeo& Naiyanetr,1999 ¤. Kanpota- mon duangkhaei Ng& Naiyanetr,1993 ¤. Thaiphusasirikit (Naiyanetr,1992) ¤. Pudaengoninor- natum (Rathbun, 1904) ¤. Pudaengonhinpoon Ng& Naiyanetr,1995 ¤. Pudaengonkhammouan Ng& Naiyanetr,1995 ¤. Pudaengonmukdahan Ng& Naiyanetr,1995 ¤. Pudaengonsakonnakorn Ng& Naiyanetr,1995 ¤. Pudaengonthatphanom Ng& Naiyanetr,1995 ¤. Pudaengonwanonni- wat Ng& Naiyanetr,1995 ¤. Nemoronnomas Ng, 1996¤. Rathbunamonlacunifer (Rathbun, 1904)¤. Pilosamonlaosense (Rathbun, 1904) ¤. Flabellamonkuehnelti (Pretzmann,1963) ¤. Fla- bellamonpretzmanni Ng, 1996¤. Esanpotamonnamsom Naiyanetr& Ng,1997 ¤. Tomaculamon stenixys Yeo& Ng,1997 ¤. Tomaculamonpygmaeus Yeo& Ng,1997 ¤. Erebusacalobates Yeo & Ng, 1999¤. Stelomonpruinosum (Alcock,1909) ¤. Stelomonkanchanaburiense (Naiyanetr, 1992)¤. Stelomontharnlod Yeo&Naiyanetr,2000 ¤. Dromothelphusapealianoides (Bott,1966) ¤. Dromothelphusaphrae (Naiyanetr,1984) ¤. Dromothelphusaprabang Yeo& Naiyanetr,1999 ¤. Potamonorleansi Rathbun, 1904 ¤. Potamontannanti Rathbun, 1904 ¤. Potamonloxophrys Kemp, 1923¤. Potamonlaevior Kemp, 1923¤. Potamonmieni Dang, 1967¤. Potamonyotdomense (Naiyanetr,1984) ¤. Potamonboonyaratae (Naiyanetr,1987) ¤. Potamondoichiangdao Naiyanetr RECOGNITION OFTWOSUBFAMILIES IN THEPOTAMIDAE 1231

& Ng, 1990¤. Potamondoisutep Naiyanetr& Ng,1990 ¤. Takpotamonmaesotense Naiyanetr, 1992¤. Potamonphuphanense Naiyanetr,1992 ¤. Potamonerawanense Naiyanetr,1992 ¤. Pota- mon maehongsonense Naiyanetr,1992 ¤. Potamonnamlang Ng& Naiyanetr,1993 ¤. Potamon jarujini Ng& Naiyanetr,1993 ¤. Potamonmaesariang Ng& Naiyanetr,1993 ¤. Potamonlipkei Ng& Naiyanetr,1993 ¤. Potamon nan Ng& Naiyanetr,1993 ¤. Potamonubon Ng& Naiyanetr, 1993¤. Potamonsomchaii Ng& Naiyanetr,1993 ¤. Potamonjinpingense Dai, 1995¤. Potamon cua Yeo& Ng,1998 ¤. Potamonguttus Yeo&Ng,1998 ¤. Potamon ou Yeo& Ng,1998 ¤. Potamon villosum Yeo&Ng,1998 ¤. Potamon lao Yeo& Naiyanetr,1999 ¤.

¤ SeeNaiyanetr & Ng,1990, 1997; Ng, 1992a, b, 1995,1996a, b, c;Ng& Naiyanetr,1993, 1998; Ng& Yeo,2001; Y eo& Naiyanetr,1999, 2000; Y eo&Ng,1997, 1998, 1999b; Y eoet al.,1999.

B. POTAM INAE (Thoracicsternite 8 with incompletelongitudinal median line). — Paratel- phusuladayanum (Wood-Mason,1871): 1male(NRM 14091);2 males,2 females(ZSI 4070/4); 1female(NRM 13895). Paratelphusulaburmensis (Bott,1966): holotype,male (MBA 58b); paratype:1 female(MBA 58b);others: 1 male,1 female(MGE III195);4 juveniles(MGE III196); 3males,4 females(ZSI 4047/1). Paratelphusulagibbosa Ng& Kosuge,1997: holotype,male (ZRC 1996.1557);paratypes: 3 males,4 females(ZRC 1996.1558-1564);others: 2 males(ZRC). Lobothelphusacrenulifera (Wood-Mason,1875): topotype,male (NHM 1909.9.2.9)(formerly ZSI 4073/4);others: 3 males,1 female(ZSI 4073/4);1 male(NHM 1908.12.8.7);syntypes of Pota- mon (Acanthotelphusa ) crenuliferum occosum Alcock,1910: 1 male,12 juveniles (ZSI 6905/3). Lobothelphusacalva (Alcock,1909): syntype,female (NHM 1909.9.2.10);others: 4 males,6 fe- males,5 juveniles(ZSI 5538/10);1 male(MGE III190);1 male,1 female(MGE III191);1 juvenile male(MBA 60a). Lobothelphusabarbouri (Rathbun, 1910): holotype,juvenile male (MCZ 7242). Lobothelphusafeae (DeMan, 1898): syntypes:1 male(MGE III255),1 male,1 female(MGE III 189),1 juvenilemale (ZMA De.102.877.BR). Lobothelphusaacanthica (Kemp,1918): 3 juvenile males(NRM 13917).

APPENDIX II Non-Indochinesecomparative material examined

A. POTAMISCINAE (Thoracicsternite 8 with completelongitudinal median line, lacking transverseridge) (East and SoutheastAsia, excluding Indochina). — Potamontumidum (Wood-Mason,1871): syntypes:1 male(NHM 1909.5.1.6),7 males(ZSI 6954/3). Potamon pealianum (Wood-Mason,1871): 4males,2 juvenilefemales (ZSI 5511/10),1 male,4 female (ZSI 6963/3,5509/ 10),1 male(ZSI 6413/3,6960/ 3);1 male,1 female(ZSI 6915/3). Potamon chinghungense Dai,Song, He, He, Cao, Xu &Zhong,1975: 1male(ZRC 1997.749). Potamon  exum Dai,Song, Li &Liang,1980: 1male(ZRC 1997.750). Potamonboshanense Dai & Chen, 1985: 1male(ZRC 1998.811). Potamonmenglaense Dai& Cai,1998: 1male,1 female (ZRC). Potamiscusannandalii Alcock,1909: syntypes:1 male,1 female(NHM 1909.9.2.5). Potamiscusdecourcyi (Kemp,1913): holotype,male (ZSI 8006/10). Potamiscusyunnanense (Kemp,1923): holotype,male (ZSI 792/1). Potamiscusyiwuensis Dai& Cai,1998: 1 male (ZRC). Sinopotamonplanum (Dai,1992): 1male,1 female(ZRC 1998.1178). Tenuilapotamon latilum (Chen, 1980): 1male,1 female(ZRC 1998.355). Pararangunasemilunatum Dai & Chen, 1985: 1male,1 female(IZCAS). Parapotamonspinescens (Calman,1905): 1male(IZCAS). Aparapotamongrahami (Rathbun, 1929): 5males,3 females(ZRC). Yarepotamongracilipa (Dai,Song, Li &Liang,1980): 1male,1 female(IZCAS). Huananpotamonangulatum (Dai &Lin, 1979): 1male,1 female(IZCAS). Apotamonauteshainanensis (Parisi,1916): 1 male (IZCAS). Hainanpotamonorientale (Parisi,1916): syntypes:1 male(NHM 1934.2.5.3),1 male 1232 DARREN C.J.YEO&PETERK. L.NG

(MNHN-B 5261). Nanhaipotamonhongkongense (Shen, 1940): 3males,2 females,1 juvenile (ZRC 1991.1778-1783). Cryptopotamonanacoluthon (Kemp,1918): 2males,6 females(ZRC 1998.355). Ryukyum yaeyamense (Minei,1973): 1male(ZRC 1994.4452);2 females(ZRC 1994.4451). Candidiopotamonrathbunae (DeMan, 1914): 1male,1 female(ZRC 1984.7560- 7561). Geothelphusaalbogilva Shy, Ng& Yu, 1994: 1male,2 female(ZRC 1998.212). Stoliczia stoliczkana (Wood-Mason,1871): 1male(ZRC 1989.2013). Johoratiomanensis (Ng & Tan, 1984): 2males(ZRC 1996.1742). Malayopotamonbrevimarginatum (DeMan, 1892): 2 males (ZRC 1998.1154). Isolapotamonkinabaluense (Rathbun, 1904): 1male,1 female(ZRC 1990.465- 466). Ibanumaethes Ng 1995: holotype,male (ZRC 1995.271);paratype: 1 female(ZRC 1995.272). Cerberusatipula Holthuis,1979: holotype,male (RMNH D31968);paratype, male (RMNH D 31983). Ovitamonartifrons (Bürger ,1894): 1male,1 female(ZRC 1992.8361-8362). Insulamon unicorn Ng& Takeda,1992: paratype,male (ZRC 1992.8360). Daipotamonminos Ng& Trontlej, 1996: holotype,male (ZRC 1996.1044);paratypes: 2 females(ZRC 1996.1045,1046), 1 female (IZCAS). Allopotamontambelanense (Rathbun, 1905): holotype,male (USNM 23369);paratype: female(USNM 23369). Mindoronpala Ng& Takeda,1992: holotype,male (NSMT -Cr11224). Carpomonpomulum Tan& Ng,1998: holotype,male (BPBM 5575).

B. POTAM INAE (Thoracicsternite 8 with incompletelongitudinal median line) (Mediter- raneanand AsiaMinor). — Acanthopotamonfungosum (Alcock,1909): syntypes:1 male,1 fe- male(NHM 1909.9.2.7-8). Himalayapotamonatkinsonianum (Wood-Mason,1871): 1 male, 1 fe- male,1 juvenile(ZSI 6415/3);1 male(ZRC); 1male(MBA 865a). Potamon (Potamon) bifarium Alcock,1909: syntype,male (NHM 1909.9.2.3). Potamon uviatile (Herbst,1785): 1 male, 1 fe- male (ZRC). Potamonpotamios (Olivier,1804): 1male(ZRC). Potamonpalaestinense Bott, 1967: 2males,4 females(ZRC 1998.66). Potamonalgeriense Bott, 1967: 1male(ZRC). Socotrapotamon nojidense Apel &Brandis,2000: 1male,1 female(ZRC 2000.2232). Socotrapotamonsocotrense (Hilgendorf,1883): 1male,1 female(ZRC 2000.2233).

LITERATURE CITED

ALCOCK,A.,1909.Diagnoses of newspecies and varieties of freshwatercrabs. Nos. 1-3. Records oftheIndian Museum, 3: 243-252. ——,1910.Brachyura I. Fasc.II. TheIndian freshwater crabs – Potamonidae.Catalogue of the Indiandecapod Crustacea in thecollection of theIndian Museum. Calcutta: 1-135, pls. 1-14. ANNANDALE, N. & S. KEMP,1913.The Crustacea Decapoda of theLake of Tiberias. Journal and Proceedingsof theAsiatic Society of Bengal,Calcutta, 9 (6):241-258, pls. 12-14. APEL, M. & D. BRANDIS,2000.A newspecies of freshwater crab (Crustacea: Brachyura: Potamidae)from Socotra Island and description of Socotrapotamon n.gen.Fauna of Arabia, 18: 133-144. BOTT,R.,1966.Potamiden aus Asien ( Potamon Savigny und Potamiscus Alcock)(Crustacea, Decapoda).Senckenbergiana Biologica, Frankfurt, 47:469-509,pls. 16-21. ——,1967.Potamidae (Crustacea Decapoda) aus Afganistan, Westasien und dem Mittelmeerraum. VidenskabeligeMeddelelser fra Dansk Naturhistorisk Forening, Copenhagen, 130: 7-43, pls. 1-4. ——,1970a.Betrachtungen ü berEntwicklungsgeschichte der Sü sswasserkrabben nach der Samm- lungdes Naturhistorischen Museums in Genf/ Schweiz.Revue Suisse de Zoologie, 77 (2): 327- 344,pls. 1, 2, maps1, 2. ——,1970b.Die Sü sswasserkrabben von Europa, Asien, Australien und ihre Stammesgeschichte. EineRevision der Potamoidea und Parathelphusoidea (Crustacea, Decapoda). Abhandlungen derSenckenbergischen Naturforschenden Gesellschaft, Frankfurt, 526:1-338,pls. 1-58. RECOGNITION OFTWOSUBFAMILIES IN THEPOTAMIDAE 1233

BOUVIER,E.-L.,1917.Sur la classiŽ cation des Eupotamonea, crabes d’ eau douce de la famille des Potamonides.Comptes Rendus Acadé mie des Sciences, Paris, 165: 613-621. BRANDIS,D.,2000.The taxonomical status of thefreshwater crab genus Potamiscus Alcock,1909 (Decapoda,Brachyura, Potamidae). Senckenbergiana Biologica, Frankfurt, 80 (1/2):57-100. ——,2001.On the taxonomy and biogeography of Potamonatkinsonianum (Wood-Mason,1871) and Potamon (Potamon) emphysetum (Alcock,1909). Hydrobiologia, 452: 89-100. ——,2002.On the taxonomic status and biogeography of theIsolapotamidae Bott, 1970 (Decapoda, Brachyura).Journal of Natural History, London, 36 (11):1291-1339. BRANDIS, D., V. STORCH & M. TÜRKAY,2000.T axonomyand zoogeography of thefreshwater crabsof Europe, North Africa, and the Middle East (Crustacea, Decapoda, Potamidae). SenckenbergianaBiologica, Frankfurt, 80 (1/2):5-56. CHUENSRI,C.,1973.Freshwater crabs of Thailand: 1-49. (College of Fisheries,Kasetsart Univer- sity). ——,1974a.Freshwater crabs of Thailand. Kasetsart University Fisheries Research Bulletin, Bangkok, 7: 12-40. ——,1974b.Key to freshwater crabs (excluded Pseudothelphusidae and Potamocarcinidae): 1-52. (Collegeof Fisheries,Kasetsart University). DAI,A.Y.,1999.Fauna Sinica (Arthropoda. Crustacea. Malacostraca. Decapoda. Parathelphusidae. Potamidae):1-501, 238 Ž gs.,30 pls.(Editorial Committee of Fauna Sinica, Academia Sinica, SciencePress, Beijing). GUINOT,D.,1977.Propositions pour une nouvelle classiŽ cation des Crustacé s Décapodes Brachy- oures.Comptes Rendus Hebdomadaires des Sé ances de l’ Académie des Sciences, Paris, (D) 285:1049-1052. ——,1979.Donné es nouvellessur la morphologie, la phylogenè se et la taxonomie des Crustacé s Décapodes Brachyoures. Mé moires du Musé um national d’ Histoire naturelle, Paris, 112: 1- 354,pls. 1-27. INTERNATIONAL COMMISSIONON ZOOLOGICAL NOMENCLATURE (ICZN),1964. Opinion 712. Forty-sevengenera of DecapodCrustacea: placed on theOfŽ cial List. Bulletin of Zoological Nomenclature, 21 (5):336-351. KEMP,S.,1913.Zoological results of the Abor Expedition, 1911-1912. XX. CrustaceaDecapoda. Recordsof the Indian Museum, 8:289-310,pls. 17-21. ——,1918a.Zoological results of a tourin the Far East. Decapod and stomatopod Crustacea. Memoirsof the Asiatic Society of Bengal, 6: 210-297. ——,1918b.Crustacea Decapoda of theInlé Lake Basin. Records of the Indian Museum, 14: 81- 102,pls. 24, 25. ——,1923a.On a collectionof rivercrabs from Siam and Annam. Journal of theNatural History Societyof Siam, 6 (1): 1-42. ——,1923b.Zoological results of the Percy Sladen Trust Expedition to Y unnanunder the leadership ofProfessorJ. W.Gregory,F .R.S. (1922).Decapod Crustacea. Journal of theAsiatic Society ofBengal,(n.s.) 19:437-445,pl. 18. NAIYANETR, P., 2001. Potamongalyaniae n.sp., a newfreshwater crab from Thailand (Decapoda, Brachyura,Potamidae). Crustaceana, 74 (4):401-405. NAIYANETR,P. &P. K.L.N G,1990.T wonew species of Potamon Savigny,1816 s. l. fromChi- angmaiProvince, north-western Thailand, with a noteon Potamon (Potamon) cochinchinense DeMan, 1898 (Crustacea, Decapoda, Brachyura, Potamidae). Spixiana, 13 (2):121-130. ——&——,1997. Esanpotamonnamsom ,anewgenus and new species of waterfall crab (Crustacea:Decapoda: Brachyura: Potamidae) from north-eastern Thailand. Proceedings of theBiological Society of Washington, 110 (3):417-421. NG,P. K.L.,1985.Freshwater decapod crustaceans from Pulau Tioman, West Malaysia. Zoologi- scheMededelingen, Leiden, 59 (14):149-162. 1234 DARREN C.J.YEO&PETERK. L.NG

——,1987.A revisionof the Malayan freshwater crabs of thegenus Johora Bott,1966 stat. nov. (Decapoda:Brachyura: Potamidae). Malayan Nature Journal, 41: 13-44. ——,1988.The freshwater crabs of Peninsular Malaysia and Singapore: i-viii, 1-156, Ž gs.1- 63,4 col.pls. (Department of Zoology, National University of Singapore, Shinglee Press, Singapore). ——,1992a.A newgenus of cavernicolous crab (Brachyura: Potamidae) from Kanchanaburi, Thailand,with comments on thegenera Tiwaripotamon Bott,1970 and Larnaudia Bott, 1966. Mémoires de Biospé ologie, 19: 159-167. ——,1992b.Crabs of the Stolicziastoliczkana (Wood-Mason,1871) species complex (Crustacea: Decapoda:Brachyura: Potamidae). Malayan Journal of Science, 14: 1-25. — —, 1996a. Nemoronnomas ,anewgenus and new species of terrestrial crab (Crustacea: Decapoda:Brachyura: Potamidae) from central Vietnam. Raf es Bulletinof Zoology, 44 (1): 29-36. ——,1996b.Establishment of twonew genera for Potamonlacunifer Rathbun,1904, and Potamon laosensis Rathbun,1904 (Decapoda, Brachyura, Potamidae) from Laos. Crustaceana, 69 (7): 898-906. ——,1996c.On a newgenus and new species of potamid crab (Brachyura) from Burma. Crustaceana, 69 (8):1005-1013. NG,P. K.L.&P. N AIYANETR,1993.New andrecently described freshwater crabs (Crustacea: Decapoda:Brachyura: Potamidae, Gecarcinucidae and Parathelphusidae) from Thailand. Zo- ologischeV erhandelingen,Leiden, 284:1-117,Ž gs.1-68. ——&——,1995. Pudaengon,anewgenus of terrestrialcrabs (Crustacea: Decapoda: Brachyura: Potamidae)from Thailand and Laos, with descriptions of seven new species. Raf es Bulletin of Zoology, 43 (2):355-376. ——&——,1998. Terrapotamonpalian sp.nov., a secondmember of the terrestrial crab genus Terrapotamon (Decapoda,Brachyura, Potamidae) from southern Thailand. Crustaceana, 71 (5):487-492. NG,P. K.L.&D.C.J.Y EO,2001.A revisionof thegenus Tiwaripotamon Bott,1970 (Decapoda: Brachyura:Potamidae), with a descriptionof a newspecies. Journal of CrustaceanBiology, 21 (1):275-287. ORTMANN,A.,1896.Das System der Decapoden-Krebse. Zoologische Jahrbü cher, (Systematik) 9: 409-453. PRETZMANN,G.,1966.Einige neue Potamoniden (Crustacea) des Himalaya-Gebietes (V orläuŽ ge Mitteilung).Entomologisches Nachrichtenblatt, 13 (1): 4-6. RATHBUN,M.J.,1904.Les crabes d’ eaudouce. Nouvelles Archives du Musé um d’ Histoire Naturelle,Paris, (4) 6:225-312,pls. 9-18. SAVIGNY,J.C.,1816.Mé moires sur les animaux sans vertè bres, 1:107,pl. 3, Žg.1. (Paris). SECRETAN,S.,1998.The sella turcica of crabsand the endophragmal system of decapods.Journal ofNatural History, London, 32:1753-1767. WOOD-MASON,J.,1871.Contribution to Indian carcinology. Journal of the Asiatic Society of Bengal, 40 (2):189-207, 449-454, pls. 11-14, 27. YEO,D.C.J.&P. N AIYANETR,1999.Three new species of freshwater crabs from northern Laos,with a noteon Potamiscus (Ranguna) pealianoides Bott,1966 (Crustacea, Decapoda, Brachyura,Potamidae). Zoosystema, 21 (3):483-494. ——&——,2000.A newgenus of freshwater crab (Crustacea: Decapoda: Brachyura: Potamidae) fromThailand, with a descriptionof a newspecies. Journal of Natural History, London, 34 (8): 1625-1638. YEO,D.C.J.,P. N AIYANETR & P. K. L. NG,1999.Revision of thewaterfall crabs of thegenus Demanietta Bott,1966 (Decapoda: Brachyura: Potamidae). Journal of Crustacean Biology, 19 (3):530-555. RECOGNITION OFTWOSUBFAMILIES IN THEPOTAMIDAE 1235

YEO,D.C.J.&P. K.L.N G,1997.On a newgenus of riverine crab (Crustacea: Decapoda: Brachyura:Potamidae) from northwestern Thailand, with descriptions of two new species. Hydrobiologia, 350: 179-188. ——&——,1998.Freshwater crabs of the Potamontannanti speciesgroup (Crustacea, Decapoda, Brachyura,Potamidae) of northernIndochina. Raf es Bulletin of Zoology, 46 (2):627-650. ——&——,1999a.The state of freshwatercrab taxonomy in Indochina(Decapoda, Brachyura). In: F. R. SCHRAM & J. C. VON VAUPEL KLEIN (eds.),Crustaceans and the Biodiversity Crisis,Proceedings of theFourth International Crustacean Congress, 1998, 1: 637-646. ——&——,1999b. Erebusacalobates ,newgenus, new species, a troglobiticcrab (Brachyura: Potamidae)from Laos. Journal of Crustacean Biology, 19 (4):908-916.

Firstreceived 24 June2003. Finalversion accepted 19 August 2003.