Gammarellns 387 



1. G. homari (F.) \n9 Astacush., J. C. Fabricius, Reise Korweg., p.247 j 1788 

 Cancer (A.) h., .7. F. Gmeliu, Syst. Nat., u. 1 p.2986 | 1798 Gammarus h., J. C. Fabricins, 

 Ent. syst., Suppl. p.4l8 | 1S88 Amathüla h., T. Stebbing in: Rep. Voy. Challenger, f. 29 

 p.45 etc. 1 1893 A. h. (part.), A. Della Valle in: F. Fl. Xeapel, n 20 p. 685 t. 59 f. 90 | 

 1894 A.h., T. Stebbing in: Bijdr. Dierk., u 17 p. 40 | 1894 A. h., ö. ü. Sars, Crust. 

 Norway, v.l p.490 1. 172, 1. 173 f . 1 | 1895 A.h., A. O. Walker in: Ann. nat. Hist., ser.6 

 V. 15 p. 466, 471 I 1899 Gammarellus h., T. Stebbing in : Tr. Linn. Soc. London, ser. 2 

 v.l p. 423 I 1780 Oniscus arenarius (non Slabber 1769!), O. Fabricius, Fauna Groenl., 

 p. 259 I 1887 Amathilla arenaria, H. J. Hansen in: Vid. Meddel.. ser. 4^9 p. 149 j^l793 

 Caiicer (GammareUus) homari -(- C. (G.) arenarius, .1. F. W. Herbst, Xaturg. Krabben 

 Krebse, v.2 p. 113; p. 133 \ 1819 Gammarus sabini, Leach in: John Ross, Voy. Baiiin's 

 Bay, app. p. 63 | 1862 Grayia imbricata -\- Amathilla s. (part.j, Bäte & Westwood, ßrit. 

 sess. Crust., v. 1 p. 152; p.361 f. | 1874 A. s., Buchholz in: Zweite D. Nordpolarf., v.2 p..S46 

 Crnst. t. 8 f. 1,2; t. 9 f . 1 | 1827 Gammarus marinus (err., non Leach 1815!), Ct. Johnston 

 in: Zool. J., v.3 p. 176 | 1828 Gr. carinatus (non J. C. Fabricius 1793!), G. Johnston 

 in: Zool. J., v. 4 p. 52 | 1857 Amathia carinata, A. White, Hist. Brit. Crust., p. 182 | 

 1851 Amphitho'e mogyridgei, Bäte in: Ann. nat. Hist., ser. 2 v.l p. 318 t. 10 f. 10 | 1862 

 Grayia imbricata., Graya i. -\- Amathia sabinii -\- A. carino-spinosa (part.). Bäte, Cat. 

 Amphip. Brit. Mus., p. 101 t. 16 f. 4; p. 197 t. 35 f. 9: p. 199 t. 35 f. 11. 



Body robust in Q , more compressed in ä . Peracon segments 1 — 7 

 and pleon segments 1 — :3 with compressed dorsal caiina produced raore or 

 less backward, that of peraeon segment 1 rather broad and also a little 

 acutely produced forward; pleon segment 4 with a transverse dorsal depression 

 followed by a carina. In the young the dorsal prominences are much 

 less marked, Head depressed, rostrura small, lateral corners obtusely 

 truncate. Side-plates 1 — 4 successively larger, but in young 1*** little 

 smaller than 2"^ or 3**. 8ide-plate 4 emarginate liehind. Pleon segment 3, 

 postero-lateral corners quadrate. Eyes large, oblong reniforra, dark brown. 

 Antenna 1 in 9 about ^'3 as long as body, P* Joint not as long as 2^ and 3** combined, 

 2"^ not much longer than 3^^, tlagellum once and a half as long as peduncle, with 

 40—55 setulose joints, accessory flagellum 6- or 7-jointed. Antenna 2 a 

 little shorter, ultimate Joint of peduncle shorter than penultimate, flagellum 

 subequal to peduncle, 40-jointed, setulose and calceoliferous. Antenna 2 in ä 

 more slender than in 9, rather longer than antenna 1, peduncle longer 

 than flagellum. Gnathopods 1 and 2, 6*^' Joint oval, narrowing to hinge of 

 finger, palm setose and spinöse. Gnathopod 2 the larger. Peraeopod 5, 

 2'! Joint larger than in peraeopods 3 and 4, its bind margiu sinuous below. 

 l'ropod 3, outer ramus rather the larger, both rami setose on inner margin. 

 Telson rather louger than peduncle of uropod 3, much longer than broad, 

 tapering to a rounded apex, in the centre of which is a little emargination 

 flanked by a pair of spinules. Colour variable, olive-gTeen or white marbled or 

 banded with brown or red. L. variable, reaching44 mm (antenna 2 d: 20 mm)^ 



Arctic Ocean, North-Atlantic, North-Sea and Skagerxak (Greenland, Spitzbergen, 

 Mirman Coast, Arctic America, Norway, British Isles, France); Kattegat. Depth 0— 206in. 



2. G. angulosus (H. Kathke) 1843 Gammarus a., H. Rathke in: K.ActaAc. 

 Leop., V. 2O1 p. 72 t. 3 f. 3 1 1855 G. a., W. Liljeborg in: Vetensk. Ak. Handl.. 

 1853 p. 447 I 1871 Amathilla angulosa, A. Boeck in: Forh. Selsk. Christian., 1870 

 p.217 I 1894 A.a., G. 0. Sars, Crust. Norway, v.l p. 492 t. 173 f. 2 | 1899 Gamma-' 

 reUus angulosus, T. Stebbing in: Tr. Linn. Soc. London, ser. 2 v.l p.423 | 1862 Amathia 

 carino-spinosa (part.). Bäte, Cat. Amphip. Brit. Mus., p. 199 | 1862 Amathilla sabini (part.), 

 Hate & Westwood, Brit. sess. Crust., v. 1 p. 362 | 1893 A. homari (part.), A. Della Valle 

 in: F. Fl. Neapel, «.20 p. 685 ; 1895 A. h., A. O.Walker in: P. Liverp. biol. Soc, t7.9 p.307. 



Often confounded with but distinct from G. homari. Body short and 

 stout, in front angular, behind dorsally carinate, but carina in each segment 



36* 



