45 



A singular character of this genus, mentioned by de Haan 

 and by Boas, but by most authors neglected, is that in the 

 male the first pleon segment is without pleopods, whereas it 

 has them in the female, but of a form totally unlike the four 

 following pairs, which are biramous, with the rami very un- 

 equal, but both broad and blade-like. The first pair, on the 

 contrary, are uniramous, with a peduncle scarcely free from the 

 segment carrying it, and a cylindrical or almost linear two- 

 jointed ramus, such an appendage as might be expected 

 rather on the male than the female. 



A revision of the genus, based on adequate material, may 

 eventually show that seeming discrepancies between various 

 descriptions are due to real differences in the species 

 examined. 



UpoCtEBIA capensis (Krauss). 



1843. Gehia major, var. capensis, Krauss, Siidafrik Crust., 



p. 54. 



1892. Gehia capensis, Ortmann, Zoologische Jahrbiicher, v. 6, 



P- .54- 



1893. Gebia capensis, Ortmann, Decap. u. Schizop. Plankton- 



Exp., p. 49. 



When Krauss wrote, de Haan's remarks on the genus 

 Gehia and his figures of Gehia major from Japan had been 

 published, but the description of the species did not appear 

 till 1849, at p. 165 of the Fauna Japonica, Crustacea, decas 

 sexta. Krauss was therefore unable to determine whether 

 the form found at the Cape was specifically identical with the 

 Japanese form or distinct from it. By way of compromise he 

 named it as a variety. He was struck by the considerable 

 difference of size suggested by the name of de Haan's species, 

 a difference to which some importance may be allowed when 

 it does not stand alone. Upogebia ma /or attains a length of 

 more than three inches and a half, while Upogebia capensis 

 does not attain to two and a half. Dr. Ortmann decides that 

 the two species are distinct, but without giving the marks 

 of differentiation. To judge by de Haan's figure the 

 chelipeds in his species have the fifth joint (or wrist) much 

 more strongly dentate on the upper margin than it is in the 

 Cape species, which has a single apical tooth emerging from 

 this hair-clothed border. In the second pair of legs 

 de Haan's species has a strongly denticulate border to the 

 fourth joint, which in the Cape species appears to be free 

 from denticles, though carrying the usual immensely long 

 setae. In the fifth pair of legs the fourth, fifth and sixth 

 ioints are in both species approximately equal. The telson 



