508 PROCEEDINGS OF THE NATfONAL MUSEUM. vol.xxi. 



DESCKIPTlUi^i OF Till: SUBFAMILY. 



I»SKU330TIIIGI.X»I-IXJSIN'JE: OrtTnanti. 



BoHciacwa Milnk-Edwakds, Ami. Sci. Niit., 1853, 3rd ser., Zool,, XX, p. 207 [173], 



(iiiniily). 

 Bosciadw WiMiTii, Trans. Conn. Acad. Sci., 1870, II, p. 146 (family). 

 I'jiendothelphnshhr IUtiiiiun, Proc. II. S. Nat. Mu8., 1893, XVI, p. 649 (family). 

 l'ni'ntloiefi>liM8i»ii: Oktmann, Zool. Jalirb., Syst., 1893, VII, p. 487. 

 Potamocarcininw Oktmann, Zool. Jalirb., SyBt., 1897, X, p. 315. 



The rReiul<)tlie]i)hn8inii' are those PotanionidiT^ in which the nierus 

 of the eii(h)f,nui(h is broader than h)ng, and the cxognatli is Hhort, over- 

 reaching- tlio i.schiuni of the endofiiiath but little, if at all. 



They may be further defined as follows: The outer nuirgin of the 

 merus of the endognatli is either arcuate from the articulation of the 

 ischium to the insertion of the carpus or forms an anteroexterior angle 

 with the anterior marjiin; posterior margin usually as wide as the 

 anterior margin of the ischium. The form of the merus is either sub- 

 quadrangular or subtriangular; the carpus is inserted at the anterior 

 inner notch. Ischium without a longitudinal furrow. Kxognath con- 

 siderably shorter thau the endognath, never reaching more than half 

 the length of the merus, and often (considerably reduced. The i)alatal 

 ridges reach ({uite to the anterior margin of the buccal cavity and form 

 two lateral well-marked channels. 



Carapace transversely oval; side margins toothed or tuberculate, 

 either distinctly or indistinctly. Epigastric lobes and cervical sutures 

 present. Median furrow usually present. Front inclined, generally 

 bilobed, either straight or slightly arched and with or without a supe- 

 rior margin. An inner suborbital lobe, distinct from the orbital margin, 

 is always i)resent, and is either separated from the front by the width 

 of tlie Ihigelhun, or, when united with the front, permits the passage of 

 the tlagellum behind it into the orbit. 



TnE GENERA OF THE PSEUDOTnELPITUSINyE. 



ANALYTICAL KKY TO TIIK (iENEKA Ol' THK I'SEUDOTIIKLPHUSINilC. 



A. Postoiior iiiiuf^iii of incruH of oiidoj^nath o(|ualing the anterior margin of the 

 iHcliiiiiii, against which it ia applied. 

 B. Exognath oxcceding in length tho ischium of tlio endognath; ofl'erent 

 branchial channel with a tooth or spine projecting froni the npper 



sido near the anterior end Ejritoliocera 



B'. Exognath not o(|iialing in length the ischinni of the endognath; ofl'erent 

 brancliial ohainiel without tooth or 8]>ino. 

 C. Superior niarjiin of front projecting over the surface of the front, which 

 is strongly retreating and not vi8il)le iu a dorsal view; antero-lateial 



teetli large and spiniforni . . .- J'otamocaroinm 



C. Superior margin loss advanced than inferior margin, or about ecjually 

 advanced with it; anterolateral teeth small, often tuberciili- 



form Pmmdolhvlphnsa 



A'. Posterior margin of morns of endognath one-half the widtli of tlie anterior 

 margin of the ischium, and articulated with the outer half of the 

 latter liathbunia 



