Apherusa 305 



Corners of little promiaence. Side-plates 1 — 3 rounded quadrangular, 4*^ 

 obliquely rounded and little widening distally. Pleon segmeut 3, postero- 

 laterai corners ending in a short blunt point, margin above smooth. Eyes 

 small, round, black. Antenna 1, 1^*^ Joint longer than 2^ and S^ combined, 

 flagellum 2 — 3 times as long as peduncle, 22-jointed. Antenna 2 longer, 

 ultimate and penultimate joints of peduncle subequal, flagellum 2—3 times 

 as long as peduncle. In ö the underside of peduncle of antenna 1 and 

 upperside of peduncle of antenna 2 bave fascicles of setae (Bate's flgure; 

 but flagellum of antenna 2 much longer than he represents). Gnathopods 1 

 and 2, 5*^ Joint shorter than the narrow oblong 6*^, which has a short 

 rather oblique palm. Gnathopod 2 larger than gnathopod 1, having the 

 5*^ Joint stouter and the 6*'i longer, Peraeopods 1 — 5, 4"^'* Joint a little 

 widened, shorter than 6**^, finger streng. Peraeopods 3 — 5, 2*^ Joint oval, 

 in peraeopod 5 oblong oval, much larger than in the other peraeopods. 

 Uropod 3, rami not greatly longer than peduncle, extending much beyond 

 uropod 2. Telson triangulär, scarcely twice as long as broad, tip pointed, 

 simple. Colour uniformly claret-red. L. 7-5 mm. 



Arctic Oceaii, North- Atlantic, North-Sea and English Channel (North-Norway, 

 depth 11 — 19 m; Great Britain, among shore weeds). 



2. A. tridentata (Bruz.) 1859 Faramphithoe t., R. M. Bruzelius in: Svenska 

 Ak. Handl., n. ser. r.'d nr. 1 p. 74 t. 3 f. 13 | 1861 Amphithopsis t., A. Boeck in: Forh. 

 Skand. Natnrf.. Mede 8 p. 602 , 1862 Dexaminet., Bäte. Cat. Amphip. Brit. Mus.. p.376| 

 1871 Halirages tridentatus, A. Boeck in: Forh. Selsk. Christian., 1870 p. 196 | 1876 

 H. t., A. Boeck, Skaud. Arkt. Amphip., v.2 p. 341 ! 1893 Apherusa tridentata, G. 0. 

 Sars, Crust. Norway, v. 1 pA42 1. 156 f . 1 ! 1893 Acanthozone fulvocincta (part.), A. Della 

 Valle in: F. Fl. Neapel, v. 20 p. 614. 



Peraeon segment 7 and pleon segments 1 and 2 each produced into a dorsal 

 tooth. Head, rosti'ura small, lateral corners rounded, sharply defined below, 

 post-antennal corners prominent, acute. Side-plate 1, front corner rather 

 angular, 1^* — 3*^ with lower margin minutely serrate, 4**^ much widened distally. 

 Pleon segment 2, lower part of bind margin serrate, segment 3, postero-lateral 

 corners sharply produced, margin above broadly lobed, cut into 12 upturned 

 teeth. Eyes oval reniform, dark, larger in ö than in . Antenna 1 in 9 , 

 about ^/.. length of body, P* Joint as long as 2*^ and 3^ combined, flagellum 

 rather over twice as long as peduncle, with 40 joints, l^Hhe largest. Antenna 2 

 nearly twice as long, ultimate and penultimate joints of peduncle subequal, 

 flagellum slender, about thrice as long as peduncle. Mandible, molar strong. 

 Gnathopods 1 and 2, b^^ and 6*^ joints slender, subequal, 6**" slightly widening 

 distally, palm short, defined by an obtuse angle. Peraeopods 1 — 5 moderately 

 robust, 2^ Joint in peraeopods 3 — 5 oval, with serrate bind margin, largest in 5*^ 

 pair. Uropod 3 reaching not greatly beyond the othersr inner ramus rather the 

 longer, outer edge bulging at the base. Telson oblong oval, not quite twice 

 as long as broad, apical border irregularly serrate, with some of the teeth 

 double. Colour mottled with a magnificent carmine red. L. § attaining 14 m. 



Arctic Ocean (Norway southward to Lofoten Isles). 



3. A. bispinosa (Bäte) 1857 Dexamine b., Bäte in: Ann. nat. Hist., ser. 2 

 «;. 19 p. 142 I 1871 Halirages bispinosus, A. Boeck in: Forh. Selsk. Christian., 1870 

 p.l95 I 1876 H.b., A. Boeck, Skand. Arkt. Amphip., v.2 p.338 t.23 f. 9 | 1881 Pherusa 

 bispinosa, Nebeski in: Arb. Inst. Wien, v.3 p. 146 | 1893 Acanthozone b., A. Della Valle 

 in: F. Fl. Neapel, i7.20 p. 609 t. 3 f . 5 ; 1. 17 f. 22— 36 [ 1893 Apherusa b., G. 0. Sars, 



Das Tierreich. 21. Lief.: T. R. R. Stebbing, AmpMpoda I. 20 



