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pleopoda; with the Lampropidce in the presence of rudimentary exopodites to the 
3rd and 4th pairs of legs in the female. From both these families it differs 
conspicuously in the structure of the telson, and the uniarticulate inner ramus of 
the uropoda. The marine forms of this family are very few in number, and 
belong to two nearly-allied genera, to he described below. On the other hand, 
as recently stated by the present author, this family is very abundantly repre¬ 
sented in the Caspian Sea, exhibiting in this isolated basin quite a wonderful 
variety of form. No less than 13 different species have hitherto been detected, 
and some of these differ so widely in their external appearance from the marine 
forms, that at first sight they might easily he supposed to belong to quite diffe¬ 
rent families. A closer examination has proved, however, that they all agree in 
the more essential anatomical features first pointed out in the genus Pseudocuma, 
and for this reason they have all been described as members of this genus. If, 
however, the establishment of the family Pseudocumidce be sanctioned, of course 
a more general value must be ascribed to several of these characters; and indeed 
I am now of opinion that the Caspian species ought to be referred to several 
distinct genera comprised within the present family, only one of them, P. cerca- 
roides belonging to the type genus. The other species I propose to arrange 
as follows: 
Gen. 1 , Pterocuma, G. 0. Sars, with the species pectinata. Sowinskyi and 
rostrata; gen. 2, Stenocuma, G. 0. Sars, with the species gracilis, graciloides, 
tmuicauda and diastyloides ; gen. 3, Schizorhynchus with the species bilamellatus, 
eudorelloides, scabriusculus and dbbreviatus ; gen. 4, Caspiocuma with the species 
campylaspoides. 
Gen. 1 . Pseudocuma, G. 0. Sars, 1864. 
Syn: Lexicon, v. Beneden (not Kroyer). 
Generic Characters. —Body not very slender, with the anterior division well 
marked off from the posterior. Integuments thin, exhibiting a densely squamous 
structure. Carapace of moderate size, dorsal face flattened and sloping in front, 
lateral faces generally sculptured with oblique plicse, pseudorostral projection 
more or less prominent, with the lateral parts contiguous along the dorsal line, 
subrostral corners obtusangular. Exposed segments of trunk unarmed. Tail 
