472 Gammarus 



G.p., Niphargus (purt.)?. Bäte. Cat. Ampliip.Brit.Miis., p.2l7 i 1888 G. (N.)p., T.Stebbing 

 iu: Rep. V03'. Challenger, r. 29 p. 253 1 1890 -A'. p., Wrzeöniowski in: Z. wiss. Zool., t;. 50 

 p. 603, 673 I 1865 Gammarus veneris, Cani. Heller in: Verh. Ges. Wien, r. 15 p. 981 | 

 1894 G. V., Chevreux in: Bull. Soc. zool. France, r. 19 p. 171 f. | 1895 G. v., Chevreux 

 in: Kev. biol. Nord France, v.7 p. 159. 



Near to G. marinus. Body slender aiul compressed, pleon segments 4 

 and 5 each with 1 er 2 spinulcs at 4 points of back, segment 6 with spines 

 apparently only at 2 points. Head, lateral lobes rather obliquely truncate, 

 post-antennal corners almost acute. Pleon segment 3, postero-lateral corners 

 produced acutely backward. Eyes naiTOW, oblong reniform, dark in spirit. 

 Anteunae 1 and 2 liable to variations in many respects. Antenna 1 nearly 

 half as long as body, 1^* Joint not longer ttian 2**, 3*^ about half as long as 2*^, 

 flagellum twice as long as peduncle, 34-jointed, accessory flagellum 4 — 6- 

 jointed. Antenna 2 considerably shorter, Avith longer peduncle, penultimate 

 Joint of peduncle stouter than ultimate, but scarcely so long, flagellum sub- 

 equal to peduncle, 16-jointed, the calceoli short and broad. Maxillipeds, 3*^ Joint 

 of palp slightly cuiTed and distally widened. Gnathopods 1 and 2, 6*^^ Joint 

 oblong oval, palm rather oblique, sliglitly sinuous and serrulate, ill-defined 

 except by the palmar spines, finger in gnathopod 1 closing more decidedly 

 against inner surface of band than in the larger gnathopod 2. Peraeopods 

 1 — 5 all slender, 2^ Joint in peraeopods 3 — 5 distally narrowed, free corner 

 quadrate, not very prominent, üropod 3 reaching much beyond the others» 

 outer ramus more than thrice as long as peduncle, 1^* Joint with spines at 

 4 points of outer and 3 of inner margin, both margins fringed with long 

 conspicuous setae, 2*^ Joint also setose, very small, inner ramus shorter than 

 peduncle, very slender, smooth on inner margin, with spines and setae on 

 outer and apex. Telson cleft to base, little longer than broad, each lobe 

 with 1 spine high up on outer margin and 2 at the narrowed truncate apex. 

 Colour grey or brownish, rarely with rusty spots. L. 6 — 12 mm. 



Italy (bot Springs?); Sicily; Cyprus (fresh water, 15 — 16m above the sea); Syria. 



22. G. marinus Leach 1815 G. ni., Leach in: Tr. Linn. Soc. London, r. 11 p. 359 | 

 1862 G. m., Bäte, Cat. Amphip. Brit. Mus., p.215 t. 38 f. 4 1 1889 G.m., A. 31. Xorma& 

 in: Ann. nat. Hist., ser. 6 vA p. 138 t. 12 f. 12 [ 1893 G. m., A. Della Valle in: F. Fl. 

 Neapel, i;.20 p.762 t.60 f. 28 | 1894 G.m., G. 0. Sars, Crust. Norway, vA p.497 1. 175 | 

 1830 G. olivii, H. 31ilne Edwards in: Ann. Sei. nat., u 20 p. 367, 372 t. 10 f. 9, 10] 

 1837 G.gracilis, H. Kathke in: Mem. pres. Ac. St.-Petersb., v.'d p. 374 t. 5 f. 7—10 1 

 1840 G. affinis, H. Milne Edwards, Hist. nat. Crust., v. 3 p. 47 | 1843 G. poecüurus -\- 

 G. kröyern, H. Rathke in: N. Acta Ac. Leop., v. 20i p. 68 t. 4 f. 2; p. 69 t. 4 f. 1 j 1851 

 G. locustoides, F.Brandt in: Middendorff, Reise Sibirien, ». 2i j). 139 t. 6 f. 30 a — c. 



Body slender and compressed, pleon segments 4 — 6 each dorsally 

 carrying 2 upward converging rows of spinules, each row having 6^9 spi- 

 nules in 2 slightly separated groups. Head, lateral lobes vertically trun- 

 cate. Side-plates 1 — 4 not very deep, 4*^ scarcely as broad as deep. Pleon 

 segments 2 and 3, postero-lateral corners acutely quadrate. Eyes narrow, 

 long, oblong reniform, dark. Antenna 1 nearly half as long as body, 1^* Joint 

 as long as 2^ and 3*^ combined, flagellum more than twice as long as peduncle, 

 33-jointed, accessory flagellum about 7-jointed. Antenna 2 sometimes con- 

 siderably shorter, flagellum rather longer than peduncle. Gnathopod 1, oblong 

 oval, palm slightly oblique, both 5*^ and 6*'^ joints rather longer and stronger 

 in ö than in 9 . Gnathopod 2 in Q , 5*^ Joint longer than in gnathopod 1, 

 6*^ oblong, with palm nearly transverse, not larger than in gnathopod 1. 

 Gnathopod 2 in d not larger than gnathopod 1, palm nearly ti-ansverse. 



