23 



25 



Echinogammarus 481 



j Eyes small 24. E. violaceus . . . . p. 492 



\ Eyes large — 24. 



I Uropod 3, outer ramus little longer tlian inner 25. E. ibex p. 492 



24 < Uropod 3, outer ramus considerably longer 

 l than inner — 25. 



j Gnathopod I, 6tli Joint much inflated at base . 26. E. parvexii . . . . p. 493 



\ Gnathopod 1, 6th Joint not inflated at base . 27. E. polyarthrus . . . p. 493 



1. E. berilloni (Catta) 1878 Gammarus h., Catta in: Bull. Soc. Borda | 1896 

 G.h., Chevreux in: Bull. Soc. zool. France, ».21 p. 29 f. | 1899 Echinogammarus h., 

 T. Stebbing in: Tr. Linn. Soc. London, ser. 2 v.l p. 429 ! 1893 Gammarus barilloHi, 

 A. Della Valle in: F. Fl. Neapel, v. 20 p. 765. 



Form of body nearlj as in Gammarus pulex (p. 474). Peraeou Seg- 

 ment 7 sometimes with dorsal spines; pleon Segments 1 — 3 with dorsal 

 spines in great numbers mingled with setae (only with setae in one ö spe- 

 cimen (Chevreux)); 30 — 50 spiues on segment 2, 4 — 8 dorsal spines on 

 Segment 4, 2 — 4 on segment 5, 2 or 3 on segment 6. Head, post-antennal 

 augles acute. Pleon segment 3, postero-lateral corners acute, Eyes large, 

 reuitorm. Antenna 1 not much longer than antenna 2, 1^* Joint not much 

 longer than 2<^, flagellum 25 — 30-jointed, accessory flagellum with 6 veiy 

 Short joiuts. Antenna 2, ultimate and penultimate joints of peduncle long, 

 subequal, flagellum shorter thauboth combiued, without calceoli. Gnathopod 1, 

 6*^ Joint oval, palm oblique, scarcely distinct from hind margiu. Gnathopod 2 

 in both sexes much larger than gnathopod 1, in d ß*"^ Joint of the same shape 

 as in gnathopod 1, in 9 more oblong, palm well defined from hind margin, emar- 

 ginate in the centre. Peraeopod 1 strougly setose on hind margin, setae much 

 longer than on peraeopod 2. Peraeopods 3 — 5 shorter and more robust than in 

 Gammarus pulex, with fascicles of long setae. Uropod 3, outer ramus very 

 elongate, with long setae and fascicles of spines on the margin, 2*^ Joint 

 obsolete, inner ramus not ^e length of outer, carry ing a few setae and an 

 apical spinule. Telson broader than long, lobes divergent, each with 2 spines 

 and many setae at narrowly truncate apex, and usually with 1 spine on outer 

 margin. Colour greenish brown or reddish brown. L. 9 7 mm, ö 10 — 12 mm. 



Pyrenees, to a height of 750 m ; Jersey. Streams. 



2. E. verrucosus (Gerstf.) 1858 Gammarus v.^ Gerstfeldt in: Mem. pres. Ac. 

 St.-Petersb., «).8p.282 | 1862 G. v., Bäte, Cat. Aniphip. Brit. Mus., p.219t. 39f. 1 | 1874 

 G. V., B. Dybowsky in: Horae Soc. ent. Ross., v.lQ suppl. p. 67 t. 4 f. 12 | 

 1888 G. V., T. Stebbing in: Rep. Yoy. Challenger, ?;. 29 p. 309 | 1899 

 Echinogammarus V., T. Stebbing in: Tr. Linn. Soc. London, ser. 2 v.l 

 p. 429 j 1893 Gammarus jnmgens (part.)?, A. Uella Valle in: F. Fl. 

 Neapel, u20 p. 768. 



Pleon Segments 1 — 6 (Fig. 89) pectinate with rows of 

 spinules on rather obliquely set ridge-like or tuberCUlar dorsal 

 prominences, usually forming 3 transverse series (spines 54) on 

 segment 1, 5 series (spines 89) on segment 2, 5 series (spines 100) 

 on segment 3, 2 series on each of Segments 4 — 6 (spines 32, 

 24, 12). Pleon segment 3, postero-lateral corners approximately 

 quadrate (produced into long upturned tooth. Bäte, but?). Eyes flat, ^^s- ^^^ 

 almost linear reniform, black. Antenna 1 not much longer than Do7sa"view"^of 

 antenna 2, flagellum 35 — 59-jointed, accessory flagellum 4 — 10- pieon. [After 

 jointed. Antenna 2, flagellum 1 5— 26-jointed, short, broad, flattened, ^- ^ybowsky.] 

 with calceoli in both sexes. Gnathopods 1 and 2, 6*'^ Joint tolerably roundish- 

 triangular (authors' accounts differ). Peraeopods 3 — 5, 2'^ Joint moderately 



Das Tierreich. 21. Lief.: T. E. R. Stebbing, Amphipoda I. 31 



