of the " Genus " Pencus. 523 



List of the Species o/Trachypeneus^ Alcock. 



1. Trachijpeneus barhatus (De Haan), Faun. Japon., Crust, p. 192, 



pi. xhi. tig. 3. — Japan. 



{Traclnipeneus curvirostris (Stimpson), Proc. Acad. Nat. Sci. Philad. 

 1860, p. 44. — Japan. Probably identical with T. barbatus = P. a-ffinis 

 barbatus, De Haan.) 



{Tracliypeneus granulosus (Ilaswell), P. L. S. N. S. Wales, 1879, 

 p. 41, and Cat. Austral. Crust, p. 202. — N.E. Australia. Probably, 

 as other authors also have thought, identical with T. curvirostris 

 = T. barbatus.) 



{Trachypeneus anchoralis (Spence Bate), 'Challenger' Macrura, 

 p. 258, pi. XXXV. fig. 1. — Arafura Sea ; Japan. Probably, as 

 other authors have thought, a synonym of T.granulosus= T. curvi- 

 rostris &c.) 



2. Trachypeneus asper, Alcock, sp. n. — Persian Gulf; Coroiuandel 



coast ; AndaiTiMns. 



3. Trachypeneus constrictus (Stimps(jn), Ann. Lye. Nat. Hist. N. York 



X. 1874, p. 135. — Atlantic coast of U.S. America ; West Indies. 

 Trachypeneus constrictus, var. similis (S. 1. Smith), Proc. U.S. Nat. 

 Mus. viii. 188-j, p. 175. — Atlantic coast of U.S. America ; West 

 Indies. 



7. XiPHOPENEUs, S. I. Smith. 



Xiphojmieus, S. I. Smith, Amer. Jouru. Sci xlviii. 1869, p. 390: see 

 also Proc. U.S. Nat. Mus. viii. 1885, p. 1888. 



Type, A''. Kroyeri, Heller. 



Rostrum toothed dorsally only. Antero-inferior angles of 

 carapace subdentiform. Postautennular sulcus defined only 

 ventrally. 



Carapace with longitudinal and transverse sutures_, but the 

 former is not prolonged to the posterior border. 



One of the antennuiar flagella is very long. Endopodite 

 of maxillule short, unsegmented. All the thoracic legs have 

 exopodites. 



Epipodites are absent from the third maxilh'peds and last 

 two pairs of thoracic legs. No pleurobranchise on the last 

 two thoracic somites. 



The last two pairs of thoracic legs are of great length, their 

 three terminal joints forming a long slender flag ellum. 



The branchial formula is : — 



