CRUSTACEA CASPIA. 469 



palm less oblique than iu the anterior ones (fig. 4). In the malej both pairs 

 (figs. 16, 17) are very powerfully developed, with the propodos exceedingly 

 large, especially iu the posterior pair (fig. 1 7), and of obloug oval form, the 

 palm being much shorter than the hind margin. 



The 2 anterior pairs of pereiopoda (fig. 6) exhibit the usual slender 

 form, and are but sparingly setous. 



The 3 posterior pairs (figs. 8 — 10) are moderately elongated, the basal 

 joint being in none of them particularly expanded, that of the last pair 

 (fig. 10) not differing much either iu size or shape from that of the pen- 

 ultimate pair (fig. 9). 



The last pair of uropoda (fig. 1 2) are rather elongated, especially in the 

 male (see fig. 11), projecting considerably beyond the others. The outer 

 ramus is sub-linear in form, and exhibits, on each side, 2 or 3 fascicles of 

 slender spines. The terminal joint of this ramus is very narrow, spiniform, 

 and tipped with 2 unequal bristles. The inner ramus exhibits the usual 

 rudimentary appearance. 



The telson (fig. 1 3) is very short, being nearly twice as broad as it is 

 long, and is cleft to the base by a rather narrow incision. The lateral lobes 

 are obtusely truncated at the tip, and do not exhibit any trace of apical 

 spines, whereas 2 juxtaposed, delicate bristles are found on each lobe ex- 

 teriorly, at a short distance from the tip. 



Occurrence. — Of this diminutive species a few, not very well preserved 

 specimens are contained in the collection of Dr. Grimm. They were taken 

 in the southern part of the Caspian Sea, from the considerable depth of 

 108 fathoms. Another specimen was found farther north, in a depth of 40 

 fathoms. 



21. Gammarus Andrussowi, G. 0. Sars, u. sp. 



(PL 10, figs. 18—26). 



Specific Characters. — Body rather slender and compressed. Lateral 

 lobes of cephalon transversely truncated. Coxal plates comparatively larger 

 than in G. pauxillus, 4th pair rather broad, and angularly produced below 

 the posterior emargination. Epimeral plates of metasome about as in the 

 said species. Urosome with the 2 anterior segments spinulose both dorsally 

 and laterally. Eyes not very large, oval reniform. Superior antennae much 

 longer than the inferior, joints of the peduncle successively diminishing in 

 size, flagellum very slender, accessory appendage 4-articulate. Gnathopoda 

 in female very unequal, the anterior ones being much the stronger, and hav- 

 ing the propodos rather large; posterior ones extremely slender, with the 



^H3.-MaT. CTp. 299. aq 32 



