506 Carinogammarus 



aegments to end of pleon, segments 4 — 6 with no median carina. Eyes oval- 

 Antennae 1 and 2 subequal, Vs ^s long as body. Gnathopod 1 the larger, 

 5*** Joint Short, cup-shaped, 6*^ broadly oblong oval, palm slightly concave, 

 slightly oblique, set with several short spine-teeth, finger with an obtuse 

 projection near middle of inner margin. Gnathopod 2, 6^^ Joint naiTowly 

 oblong, bind margin serrate and setose, palm transverse, sinuous, armed as 

 in gnathopod 1; finger as in gnftthopod 1. Peraeopods 1 — 5 subequal, 

 spinöse. Peraeopods 3 — 5, 2^ Joint seemingly piiiform. Uropod 3, outer 

 ramus thrice as long as inner. Telson not spinöse. L, 25 mm. 



Behring Strait. 



9. C. roeselii (Gerv.) 1755 „Squilla (Astacus) flitviatilis", Rösel, Insecten- 

 Belustig., V.3 p. 351 t. 62 f. 1—7 I 1835 Gammarus roeselii, P.Gervais in: Ann. Sei. 

 nat., ser. 2 v.i p. 128 | 1850 G. fluviatiiis (non H. Milne Edwards 1830!), G. röselii, 

 Hosius in: Arch. Naturg., n 16i p. 234 t. 3, 4 | 1899 Carinogammarus f., T. Stebbing 

 in: Tr. Linn. Soc. London, ser. 2 v.7 p. 430 | 1841 Gammarus piilex (err., non .1. C. 

 Fabricius 1775!), C. L. Koch, C. M. A., r. 36 nr. 21. 



Peraeon segment 7 prodnced to a small tooth; pleon segments 1 — 3 

 «ach rounded in front, behind produced to an acute, carinate tooth, devoid 

 of spiues, Segments 4 and 5 with slight median elevation, carrying apical 

 spines. and a raised gi'oup of spines on either side, slightly to the rear of 

 the middle one, segment 6 with a pair of slight subdorsal elevations carrying 

 spines. Head, rostrum obsolete, lateral lobes obtuse, post-antennal corners 

 produced acutely forward. Side-plates 1 — 4 rather deep, 4*^ the largest. 

 Pleon segment 3, postero-lateral corners acute. Eyes reniform, black. Antenna 1, 

 flagellum 34-jointed, accessory flagellum with 4 joints, of which 1^* und 4*^ 

 are very short. Antenna 2, ultimate Joint of peduncle longer thau penultimate, 

 flagellum 15-jointed. Gnathoppds 1 and 2 subequal, 5**" Joint short, 6*^'' pirifonn 

 in gnathopod 1, oblong in gnathopod 2. üropods 1 and 2, outer ramus 

 rather shorter thau inner. Cropod 3 probably as in C. caspius (p. 504). 

 Telson completely cleft, lobes divergent, tipped with spines. Colour greyish 

 brown with red spots, conspicuous on tips of dorsal teeth. L. 14 mm. 



Europe. Rivers and ponds. 



C. maerophthalmus (Stimps.) 1853 Gammarus m., Stimpson in : Smithson. 

 Contr., V.6 nr. 5 p. 55 j 1862 Gammaracanthus m., Bäte, Cat.Amphip.Brit.3Ins., p. 203 | 

 1893 Ceradocus? m., A. Della Valle in: F. Fl. Neapel, v.20 p.929 | 1894 Amathilla? m., 

 G. 0. Sars, Criist. Norway, v.l p. 494 | 1899 Carinogammarus? m., T. Stebbing in: 

 Tr. Linn. Soc. London, ser. 2 v.l p. 430. 



Carinate only at the pleon. Side-plates small. Eyes large, subreniform, approxi- 

 mate. Antenna 1, accessory flagellum scarcely percoptible. Uropods 1 and 2, onter 

 ramus the shorter. Uropod 3, rami broad lanceolate, shorter than in Gammarellus 

 homari (p. 387). Colour bright crimson, or red and white mottled. L. 12 mm. 



Fundy Bay (Grand Manan). Low-water mark, and Laminarian zone. 



C. mueronatus (Say) 1818 Gammarus m., Say in: J. Ac. Philad., r. In p.376 | 

 1873 G. m., (S. L Smith in:) A. E. Verrill in: Rep. ü. S. Fish Comm., v.l p. 559 | 

 1862 Gammaracanthus m., Bäte, Cat. Amphip. Brit. Mus., p. 203 | 1894 Amathilla? m.. 

 O. O. Sars, Crust. Norway, v.l p. 494 i 1899 Carinogamvtarus? m., T. Stebbing in: 

 Tr. Linn. Soc. London, ser. 2 v.l p. 430 \ 1893 Gammarus fluviatiiis (part.)?, A. Della 

 Valle in: F. Fl. Neapel, r.20 p. 729. 



Pleon Segments 1 — 3 mucronate above, but (Smith) not distinctly carinate, Seg- 

 ments 3 — 5 carrying fascicles of spines. Eyes blackish, irregularly reniform, truncate 

 above. Antennae 1 and 2 subequal. Antenna 1, flagellum 20-jointed, accessoiy 

 flagellum reaching end of 4th Joint of primary. L. less than 125 mm. 



North- Atlantic (North Carolina, Cape Cod, usually in brackish water; Florida). 



