466 Gammarus 



inner ramus very small, scale-like. Telson broader than long, the lobes each 

 naiTOwingto a blunt apex, tipped with a spine and setule. L, 8 mm. — ö unknown. 



Caspian Sea (Bay of Baku). Deptli 4 — 11 m. 



9. G. deminutus Stebb.*) 1894 G. minutus (non G. pulex m. P. Gervais 1835!), 

 G. 0. Sars in: Bull. Ac. St.-Petersb., ser. 5 v. 1 p. 347 t. 10 f. 1-26. 



Body rather sLort aud stout. Pleon segments 4 and 5 dorsally strongly 

 convex, gibbous, 4*^^ partly overlapping 5^^ dorsally, each with a very small 

 fascicle of hairs, segment 6 with a pair of spinules. Head, lateral lobes 

 broadly rouuded, rather prominent. Side-plates 1 — 4 deep, but less so in 

 ö than in Q, setose, 1^* slightly expanded, 4*^ not nearly as broadas deep. 

 Pleon Segments 2 and 3, postero-lateral corners acutely quadrate. Eyes 

 not large, oblong oval, dark. Antenna 1 little raore than \'^ as long as 

 body, 1*** Joint large, nearly twice as long as 2*^ and 3'' combined. flagellum 

 subeqnal to peduncle, 8-jointed, accessory flagellum 3-jointed. Antenna 2 a 

 little sh orter, antepenultimate Joint of peduncle thick, distally projecting, ultimate 

 Joint shorter than penultimate, flagellum about half as long as peduncle, 4-jointed. 

 Gnathopods 1 and 2 in 9 small, subeqnal, 6*^ Joint oval quadrangular, palm 

 Short, almost transverse. Gnathopods 1 and 2 iu d stronger. more unequal, 

 6^^ Joint in gnathopod 1 much naiTower and with palm more oblique than 

 in gnathopod 2. Peraeopods 1 and 2, 4**^ Joint rather large, this and 5*^ 

 strongly setose on bind margin. Peraeopods 3 — 5 little differing in length, 

 2*^ Joint in peraeopod 3 subquadrate, lower bind corner nearly rectangular, 

 in peraeopod 4 much narrower, somewhat expanded above. with no free 

 corner below, bind margin sinuous, in peraeopod unusually large, front 

 margin little convex, bind margin extremely so. with broadly rounded lobe 

 produced downward. Uropods 1 and 2, rami with apical spines only. üropod 3 

 of moderate size, reaching beyond the others, peduncle short, outer ramus 

 narrow% with 1 fascicle of spines near middle of outer margin, others at 

 apex of 1^* Joint, 2*^ Joint very small, tipped with 3 setules, inner ramus 

 very small, with 1 apical spinule. Telson with divergent lobes, each having 2 

 small spinules on the obtuse apex. L. 9 4, d 5 mm. 



Caspian Sea. 



10. G. similis 0. Sars 1894 G. s., G. 0. Sars in: Bull. Ac. St.-Petersb., ser. 5 

 V.1 p. 355 t. 11 f. 11— 20. 



Very like G. compressus (p. 465), less compressed, back broad, smooth, 

 except for 2 minute spinules on pleon segment 6. Head, lateral lobes 

 obtusely rounded, prominent. Side-plates 1 — 4 setose, 1^* scarcely expanded, 

 4*^ deeper than broad. Pleon segments 2 and 3, postero-lateral corners 

 subquadrate. Eyes of moderate size, oblong reniform. Antennae 1 and 2 

 equal, scarcely more than ^/^ as long as body. Antenna 1, 1^* Joint large, 

 nearly twice as long as 2^ and 3^ combined, flagellum rather longer than 

 peduncle, 11-jointed, accessory flagellum 4- or 5-jointed. Antenna 2, 

 flagellum nearly as long as peduncle, 7-jointed. Gnathopods 1 and 2 in Q 

 small, 6*^ Joint oblong, palm little oblique, 5*^^ and 6^^ joints longer and 

 narrower in gnathopod 2 than in gnathopod 1. Gnathopods 1 and 2 in cJ 

 more powerful, palm more oblique, 5*^ and 6*'* joints little longer but much 

 broader in gnathopod 2 than in gnathopod 1. Peraeopod 5, 2*^ Joint compara- 

 tively larger and more expanded than in G. compressus. Uropod 3 extending 

 much beyond the others, outer ramus long, setose on inner margin, 2*^ Joint 



*) Xom. nov. 



