25 



1876. Elamene whitei Miers. Cat. Crust. New Zealand, p. 52, pi. 1, f. 4. 



1S76. Elamene whitei Miers. Ann. Mag. Nat. Hist. (4) v. 17, p. 221. 



1885. Elamena whitei Filhol. Miss. ile Campbell, t. 3, prt 2, p. 403, pi. 47, f. 2 — 3. 



Hab. East coast of Stewart Island, near South Island (New Zealand). 



Trigonoplax H. Milne-Edwards. 



[853. Trigonoplax H. Milne-Edwards. Ann. Sc. Nat. (3) t. 20, p. 224. (Nee Trigonoplax 

 Stimpson, Proc. Ac. Nat. Sc. Philadelphia, 1S58, p. 109, and Smithson. Inst., Miscell. 

 Coll. v. 49, 1907, p. 146 (= Elamena).) 



The pentagonal carapace, with the postero-lateral margins very short, and the long 

 antero-lateral margins straight or concave and passing anteriorly into the triangular rostrum, the 

 very long, bulging epistome ancl the absence of a septum between the antennulae are the 

 characteristic features of the genus. Alcock l ) regards it as merely a subgenus of Elamena. 



There is only one species known, with a subspecies in Australian waters. The two forms 

 are to be distinguished thus : 

 Length of carapace exceeding breadth, front short; 



dactyli of walking legs falcate, broadest at base . T. unguiformis (de Haan) 

 Length of carapace equal to breadth, front more 



elongate; dactyli of walking legs broadest at micldle T. ung. subsp. longirostris Mc Culloch 



1 . Trigonoplax unguiformis (de Haan). 



1839. Ocypode (Elamene) unguiformis de Haan. Faun. Japon. Crust. p. 75, pi. 29, f. 1 and 



pi. H (s. n. Inachus (Elamene) unguiformis). 

 1853. Trigonoplax unguiformis H. Milne-Edwards. Ann. Sc. Nat. (3) t. 20, p. 224. 



1893. Elamene unguiformis Henderson. Transact. Linn. Soc. London (2) v. 5, p. 394. 



1894. Trigonoplax unguiformis Ortman. Zool. Jahrb. Syst, Bd 7, p. 31. 



1900. Elamena (Trigonoplax! unguiformis Alcock. Journ. As. Soc. Bengal, v. 69, prt 2, p. 387. 

 1900. Elamene unguiformis Lanchester. Proc. Zool. Soc. London, 1900, p. 761. 

 1902. Trigonoplax sp. de Man. Abhandl. Senckenb. Gesellsch., Bd 25, Heft 3, p. 500. 

 1907. Trigonoplax unguiformis de Man. Transact. Linn. Soc. London (2) v. 9, prt 11, p. 396. 

 t 

 In the Leiden Museum I found 7 of the original specimens of de Haan, dried and in 



a very bad state. As de Man's specimen (1902) did not wholly agree with de Haan's and 

 Alcock's statements, and the former author was somewhat doubtful about the identity, the 

 following remarks may be of use : 

 i° The dividing line between merus and ischium of the external maxillipeds is angular in 



de Haan's figure (pi. H), straight in de Max's specimen. In the original specimens it is 



indeed straight, only in one or two cases with a faint angulation. 

 2 The shape of the rostrum on pi. H of de Haan corresponds better with the facts than 



that of pi. 29: it is somewhat more rounded off and agrees with the rostrum of de Man's 



specimen. 



1) Journ. As. Soc. Bengal, v. 69, prt. 2, 1900, p. 386. 



2 5 



SIKOGA- EXPEDITIE XXXIX f. 



