474 Ganimarus 



form, dark. Autenna 1 not quite half as long as body, 1^*^ Joint scarcely as 

 long as 2*^ and 3^^ combined, flagellum about twice as long as peduncle, accessoiy 

 flagellum about 6-jointed. Antenna 2 considerably shorter, flagellum with calceoli 

 in ö . Gnathopods 1 and 2 in Q nearly as in G. locusta, but ö^'^ Joint of gnathopod 2 

 not so naiTOW. Gnathopods 1 and 2 in d not so strongly developed as in 

 G. locusta, and less uuequal. Peraeopods 3 — 5 not very slender, 2*^ Joint in 

 peraeopod 3 with lower bind corner rounded. üropod 3, rami densely setose, 

 inner much more slender than outer, and reaching nearly -/a of its lengih. 

 Telsou rather broader than long, each lobe with 4 apical, 1 subapical, and 

 2 — 4 lateral spines, the last near the base, the spines accompanied by long 

 diverging setae. Colour generally dark, with the usual pink marks on sides 

 of pleon Segments 1 — 3. L. d 15 mm, o smaller. 



South Greenlaud (warm Springs); Norvvay (beach. iinder stones and algae, and in 

 brackish pools above high water mark); Kattegat; Dutch coast; Guernsey; England; 

 Ireland ; lochs of Shetland, Outer Hebrides, and Perthshire. 



25. Gr. pulex (Ij.j 1758 Cancer p. (part), Linne, Syst. A'at., ed. 10 p. 633 | 1763 

 C. p., Scopoli, Ent. Carniol., p. 412 | 1775 Ganimarus p.. J. C. Fabricius, Syst. Ent., 

 p.418 I 1876 G. p., A. Boeck, Skand. Arkt. Ämphip., v.2 p. 373 t. 24 f. 7 | 1888 G. p., 

 T. Stebbing in: Kep. Voy. Chailenger, «J.29 p.44, 253, 1703 | 1894 G.p., G. O. Sars, Crust. 

 Norway, v.l p. 503 t. 177 f. 2 | 1777 Astacus p., Pennant, Brit. Zool., cd. 4 v.4: p. 17 i 

 1778 Squiüa p., (ieer, Mem. Hist. Ins., v. 7 j). 525 | 1793 Cancer (Gatnmarellus) p. 

 (part.), J. F. W. Herbst, ^'aturg. E:rabben Krebse, v. 2 p. 130 (not figure!) | 1808 

 C. {Gammarns) p.. Montagu in: Tr. Linn. Soc. London, i: 9 p. 93 t. 4 f . 2 | 1815 

 Gammarits aquaticus, Leach in: Tr. Linn. Soc. London, r. 11 p. 359 | 1830 G. fiuviatilis, 

 H. Jlilne Edwards in: Ann. Sei. nat., u 20 j). 368 | 1893 G. f. (part.), A. Delhi N'alle in: 



F. Fl. Neapel, r. 20 p. 763 ! 1835 G. fossarum, C.L.Koch, C. M. A., r. 5 nr. 2 | 1839 



G. stagnalis, Andrzeiowski in: Bull. Soc. Moscou. nr. 1 p. 23 | 1863 G. lacustris, G. 0. 

 Sars in: Nyt Mag. Naturv., r. 12 p. 206 \ 1867 G. neglectus, (t. O. Sars, Crust. d'Eau 

 douce Xorvfege, p. 46 t. 4, 5; t. 6 f. 1 — 20 | 1889 G. locusta var. B, Hoek in: Tijdschr. 

 Nederl. dierk. Ver.. ser. 2 v.2 p. 214 t. 10 f. 12, 12'. 



Pleon Segments 4 — 6 each with 2 spines in median dorsal groups and a 

 Single spine on each side. Head, lateral lobes vertically truncated, less broad 

 than in G. duebenii (p. 473). Pleon segments 2 and 3, postero-lateral corners 

 simply quadrate. Eyes small, oval, black. Antenna 1 nearly half as long as body, 

 1^' Joint not as long as 2^ and 3*^ combined, flagellum twice as long as peduncle, 

 25 — 28-jointed in d, accessory flagellum only 4-jointed. Antenna 2 con- 

 siderably shorter. flagellum 12-jointed, in d with calceoli. Gnathopods 1 

 and 2 in o rather small, 6*'^ Joint in gnathopod 1 with oblique palm, in 

 gnathopod 2 narrow, oblong, palm nearly transverse. Gnathopods 1 and 2 

 in d rather stronger, ft*'* Joint in gnathopod 1 piriform, in gnathopod 2 of 

 about the same size, but rather oblong, widening slightly to the palm which 

 is far less oblique. Peraeopods 1 — 5 slender, 2^^ Joint in peraeopod 3 with 

 lower bind coraer rounded, in peraeopods 4 and 5 without a free corner, 

 but bind margiu convex. üropod 3 long, rami fringed with long setae, 

 some plumose, inner ramus subequal in length to 1** Joint of outer (Sars) 

 or '■^|^ as long as the whole ramus (Chevreux), with a Single spine on inner 

 margin near base. Telson rather small, each lobe with 2 apical spines 

 and 1 on outer margin near the base. Colour dark or ligbt brownish green. 

 L. d reaching 20 mm, 5 smaller. 



Europe. Lakes and streams, generally distributed, found eveu in lakes 

 500- 1200 m above the sea. 



