CRUSTACEA CASI'IA.- 441 



peudage (see fig. 2) does not attain the length of the last peduncular joint, 

 and is composed of 4 Articulations. 



The inferior antennae are very feeble in structure, and scarcely half as 

 long as the superior. The basal joint is globularly tumefied, and the flagellum 

 about as long as the last peduncular joint. 



The gnathopoda (figs. 3, 4) are powerfully developed, and exhibit the 

 structure characteristic of the genus, though diff"ering, as to the relative 

 proportion of the propodos, from both the other species. In the anterior pair 

 (fig. 3) the propodos is strongly expanded distally, and almost triangular in 

 form, but is comparatively much less elongated than in 0. relictus, the 

 greatest breadth considerably exceeding half the length. The palm is evenly 

 arcuate, and somewhat longer than the liind margin, from which it is defined 

 by an obtuse corner carrying several strong spines, one of wliich is much 

 elongated. The propodos of the posterior gnathopoda (fig. 4), unlike what is 

 the case in G. relictus, is somewhat larger than that of the anterior ones, 

 and exhibits a rather different form, being broadest at the base, and gra- 

 dually tapering distally. The palm is very oblique, occupying almost the 

 whole inferior edge, and is defined behind by an obtusely rounded promi- 

 nence carrying a rather large number of strong spines arranged in 2 bundles. 



The pereiopoda appear on tJie whole less slender than in G. relictus, 

 more resembling those in the arctic species. The 2 anterior pairs are, as 

 usual, mucli smaller than the 3 posterior, and are edged witli fascicles of 

 delicate bristles (see fig. 5). Of the posterior pairs, the 2 anterior ones are 

 much elongated, even exceeding in length half the body, and have their outer 

 part closely edged with short spines. The basal joint of both these pairs is 

 rather narrow, oblong oval, and provided with a slight keel running along 

 the outer surface. The last pair are considerably shorter than the 2 pre- 

 ceding ones, and have the basal joint somewhat larger and more expanded 

 in its proximal part. 



The uropoda and telson would seem to be constructed in the very same 

 manner as in the other 2 species. 



Occurrence. — Of this pretty form, some specimens were collected by 

 Dr. Grimm in the southern part of the Caspian Sea, from a depth of 108 

 fathoms. 



Gen. AmatMllina, Grimm. 



Of this genus, established by Dr. Grimm, and apparently peculiar to 

 the Caspian Sea, the present author has described, in his 1st article on the 

 Amphipoda, 2 species: A. cristata and affinis. Three other species are now 

 added, increasing the number of species to 5 in all. 



*ji3.-MaT. CTp. 371. 21 



