24 Annals of the South African Museum. 



' MALACOSTRACA. 

 Brachyura. 



TRIBE OXYRRHYNCHA. 



FAMILY INACHIDAE. 

 GEN. ACHAEOPSIS, Stimpson. 



1857. Acliaeopsis, Stimpson, Pr. Ac, Sci. Philad., vol. 9, p. 219. 

 1873. Dorynchvs, Norman Wyville- Thorn son, Depths of the Sea, 



p. 174, fig. 34. 



1880. Lispognatlms, A. Milne-Edwards, Crust, reg. Mexicaine, p. 349. 

 1893. Aclineopsis, Ortmann, Zool. Jahrb., vol. 7, p. 36. 



1910. Acliaeopsis and Dorynchus, Stebbing, in these Annals, vol. 6, 



pt. 4, p. 285. 



1911. Achat'<>i>#ix, Eathbun, Tr. Linn. Soc. London, vol. 14, pt. 2, 



p. 247. 

 1916. Eathbun, Pr. U.S. Mus., vol. 50, p. 535. 



Additional references for the united genera will be found in 

 these Annals for 1910. A. siijierci/inrl,^, Ortmann, and the little 

 A. suluensis, Eathbun, stem to be closely related one to the 

 other, but well distinguished from other species by the large 

 median spine of the carapace. 



ACHAEOPSIS THOMSONI (Norman). 

 Plate XC. 



1873. Dorynchus thomsoni, Norman, Depths of the Sea, p. 174, fig. 34. 



1910. Stebbing, Ann. S. Afr. Mus., vol. 6, pt, 4, 



p. 286. 



1911. Acliaeopsis thomsoni, Rathbun, Tr. Linn. Soc. London, vol. 14, 



pt. 2, p. 247. 



Among many females laden with ova and smaller males the 

 specimen here figured was conspicuous by its chelipeds 

 strikingly larger than in any other specimen, and with the 

 palm very much longer than the fingers. In other respects 

 there appeared to be no trustworthy marks of difference to 

 justify the naming of a new species. The parallelism or 

 divergence of the horns of the rostrum is certainly a variable 

 character. All the specimens examined, of either sex, have the 

 strongly curved process on the ventral surface of the rostrum 



