658 Ischyrocerus 



Joint veiy little longer than 3'^, flagellum 1^2 times as long as 3*^ Joint of 

 peduncle, 7- or 8-jointed; accessory flagellum as long as 1^* Joint of primary, 

 1-jointed. Antenna 2 longcr, % as long as body; flagellum about 6-jointed. 

 Gnathopods 1 and 2 nearly alike; 6*^ Joint not large, oblong, palm very 

 oblique, ovenly convex, the defining angle not very conspicuous, marked by 

 2 palmar spines. Peraeopod 4 much longer than peraeopod 3 and peraeo- 

 pod 5 than peraeopod 4; all rather slender. üropod 3, peduncle rather 

 long, longer than peduncle of uropod 2, stout, with long rami, more than 

 half as long as peduncle. L. 4 — 5 mm. — ö unknown. 

 Baffin Bay (lat. 71 <> N., long. 59» W.). 



2. I. anguipes Kröyer 1838 I. angvipes, Kröyer in : Danske Selsk. Afh., v. 7 

 p. 283 t. 3 f. 14 a — m | 1840 I. anguipes, H. Milne Edwards, Hist. nat. Crust., v. 3 p. 56 | 

 1859 Podocerus a., R. M. Bruzelius in: Svenska Ak. Handl., n. ser. u3 nr. 1 p. 21 | 1874 

 P.a., Buchholz in: Zweite D. Nordpolarf., v.2 p.378 Crust. t.l3 f.2; 1. 14 | 1876 P.a., 

 A. Boeck, Skand. Arkt. Amphip., v.2 p. 603 t. 27 f . 5, 6 ! 1893 P. a., A. Della Valle in: 

 F. Fl. Neapel, tJ. 20 p. 444 t. 57 f. 18 | 1894 P.a., T. Stebbing in: Bijdr. Dierk., v.ll 

 p. 44 I ?1843 Gammarus zebra, H. Rathke in: N. Acta Ac. Leop., u20i p. 74 t. 3 f . 4 | 

 1851 Ischyrocerus z., W. Jjiljeborg in: Öfv. Ak. Förh., v.8 p. 23 | 1855 Podocerus z., 

 W. Liljeborg in: Vetensk. Ak. Handl., 1853 p. 446 | ?1853 Cernpus fucicola, Stimpson 

 in: Smithson. Contr., v.6 nr. 5 p. 48 t. 3 f. 34 | 1855 Ischyrocerus minutus, W. Liljeborg 

 in: Öfv. Ak. Förh., v. 12 p. 128 | 1862 Podocerus cylindricus (err.. non Say 1818!), Bäte, 

 Cat. Amphip. Brit. Mus., p. 256 t. 44 f. 4 | 1884 P. falcatus (err., non Cancer (Gammarus) f. 

 Montagu 1808!), H. Blanc in: N. Acta Ac. Leop., v.Al p. 79 t. 9 f. 96— 101 1 ?1889 

 P. isopus, A. O. Walker in: P. Liverp. biol. Soc, ».3 p. 209 t.ll f. 11—13 | ?1890 P. i., 

 A. O.Walker in: P. Liverp. biol. Soc, u4 p.250 t. 16 f. 7 1 ?1894 P. megacheir, T. Stebbing 

 in: Bijdr. Dierk., v. 17 p. 44 | 1894 Ischyrocerus anguipes, I. angvipes -\- I. minutus, Gr. 

 0. Sars, Crust. Norway, v. 1 p. 588 t. 209; p. 589 t. 210 f. 1 | 1895 J. anguipes + I. m., 

 Ohlin in: Acta Univ. Lund., v. 31 nr. 6 p. 56. 



Body rather slender. Head, lateral lobes somewhat obtuse but with a 

 minutely projecting point. Side-plates encreasing in depth from 1^* — 4**^ in Q , 

 but in ä 2^ — 4*^^ equal in depth; 5*^ with front lobe rather less deep than 4**». 

 Pleon Segment 3, postero-lateral corners rather obtusely quadrate. Eyes 

 small, rounded, dark brown. Antenna 1 about ^3 ^s long as body; 3*^ Joint 

 of peduncle much longer than 1^*, little shorter than 2*^; flagellum about 

 half as long as peduncle, attaining 9 joints, but often with fewer; accessory 

 flagellum shorter than P* Joint of primary, with 2 joints, 2*^ minute. Antenna 2 

 longer, especially in d ; flagellum about as long as ultimate Joint of peduncle, 

 5 — 7-jointed. Gnathopod 1 rather feeble, 6**^ Joint oval, distally narrow; 

 the oblique palm defined by palmar spines, finger sen-ate. Gnathopod 2 in 

 ö very large; 5*^ Joint very small, cup-shaped, 6*'^ elongate, curved; the 

 concave, hirsute bind margin or palm parallel to the convex front, and 

 forming near the finger-hinge a truncate, finely denticujate process; the finger 

 bulging a little after passing this process; palm margin occasionally straight 

 or even a little convex. Gnathopod 2 in 9 similar to gnathopod 1, but 

 more robust. Peraeopods 1 — 5 rather sti-ougly built. Peraeopods 3 — 5, 

 2^ Joint oblong oval, bind margin smooth or crenulated; finger micro- 

 scopically pectinate for some distance. üropod 3, peduncle long, rami 

 Short, outer tapering, tipped with small spines, inner (not outer) rather 

 broader, apically beut, having on upper margin 3 or 4 denticles. Telson 

 little longer than broad, obtusely tiiangular, with dorsal transverse row of 

 1 — 4 slender spines on each side. Colour very variable. L. 4 — 15 mm. 



Arctic Ocean (widely distributed) ; North- Atlantic, North-Sea and Skagerrak (Norway 

 and Bohuslän; Grand Manan; Liverpool Bay?); Kattegat; West Baltic, depth 18 m. 



