Acanthonotozoma 219 



poiut between the 2 emarginations, ö^^^ and 6^^ with bind lobe niuch produced 

 downward, obtuse. Pleon segraents 1 and 2, postero-lateral corners forming a 

 small tooth, margin above slightly serrate, in 3^ 2 diverging uarrow lobes, the 

 lower coarsely serrate on upper edge and apex. Eyes small, oval, narrow above, 

 brigbt red. Antenna 1, V^ Joint shorter than 2'^ and 3^^ combined, not dentate, 

 flagellum scarcely longer than peduncle, with about ]5 joints carrying sensory 

 filaments. Antenna 2 considerably shorter, ultimate Joint of peduncle rather 

 shorter than penultimate, flagellum shorter than ultimate and penultimate com- 

 bined. Guathopod 1, 2*^ Joint setose on both raargins, 5^^ taperiug, longer than 

 the very narrow 6*^, finger awl-shaped, not dentate, beset with curved setae, 

 the apical one densely ciliated on one edge. Gnathopod 2. 5*"^ Joint longer 

 than 6^^^, both spinöse, finger shoii;, broad, sublamiuar with acute tip. Peraeo- 

 pods 3 — 5, 2<^ Joint quadrangular, slightly produced at lower bind corner. 

 üropod 3, outer ramus about 'V* as long as inner. Telson oblong oval, distally 

 tapering. incision very short. Colour whitish, each segment with 2 or 3 narrow 

 ti'ansverse bands of brilliant crimson, which extends also to bases of limbs 

 and antenuae. L. 9 reaching 12 mm. 



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

 Barents Sea, Murman Coast, Kara Sea, North-America, .Bohuslän, Norway from Hauge- 

 siind northward). Depth 19 — 300 m. 



2. A. eristatum (J. C. Ross) 1835 Acanthonotus cristatus, J. C. Ross in: John 

 Ross, App. sec. Voy., nat. Hist. p. 90 t. B f. 8—12 | 1838 Amphithoe cristata, Kröyer 

 in: Danske Selsk. Afh.. r. 7 p. 322 | 1866 Vertummis cristatus, Goes in: Ofv. Ak. Förh., 

 «). 22 p. 522 I 1876 Acanthonotozoma eristatum. A. Boeck, Skand. Arkt. Amphip., v.2 

 p. 238 ! 1894 A. c, T. Stebbing in: Bijdr. Dierk., r. 17 p. 32 | 1893 Acanthonotosoma c, 

 G. 0. Sars, Crust. Nonvay, r. 1 p. 375 t. 131 f . 2 ■ 1862 Acanthonotus serratus (part.), 

 Bäte, Cat. Amphip. Brit. Mus., p. 127 | 1893 Acanthonotosoma serratum (part.), A.Della 

 Valle in: F. Fl. Neapel, r.20 p. 675. 



Body rather compressed, cariua conspicuous from peraeon segment 1 

 to pleon segment 4, forming a large elevated laminar tooth on each segment, 

 except peraeon segments 1 — 4. Head, lateral corners small, narrowly rounded. 

 Side-plate 4 with an obtuse point between the 2 emarginations, o*^'' and 6*^' produced 

 acutely backward. Pleon segments 1 — 3, postero-lateral corners acute, in 

 segment 3 strongly produced, not bilobed. Eyes very small, round, bright red. 

 Antenna 1, P* Joint subequal to 2<^ and 3*^ combined, l^^and 2'^ each with apical 

 tooth. flagellum subequal to peduncle, setose. Antenna 2 scarcely shorter. Gnatho- 

 pod 1, 2^^ Joint not setose, 5*'^ little longer than linear 6*'\ tinger with setae as in 

 A. serratum and distally armed with 7 curved deuticles. Gnathopod 2, 

 5*'^ Joint scarcely longer than 6*^, both setose, finger small, curved. Peraeo- 

 pods 1 — 5 rather robust. Peraeopods 3—5, 2*^ Joint oblong quadrangular, 

 produced below into two acute processes. üropod 3, outer ramus about 

 -/^ as long as inner. Telson scarcely louger than broad, apical incision 

 deeper than in A. serratum. Colour reddish white. -L. o 12 — 18-5 mm. 



Arctic Ocean (Arctic America, Spitzbergen, Barents Sea, Kara Sea, North- 

 Norway). Depth 94—246 m. 



3. A. inflatum (Kroyer) 1842 Acanthonotus inflatus., Kreyer in: Naturh. Tidsskr., 

 r.4 p. 161 I 1866 Yertnmnus i., Goes in: Öfv. Ak. Förh., r.22 p. 523 t. 38 f. 11 [ 1876 

 Acanthonotozoma inflatum, A. Boeck, Skand. Arkt. Amphip., r. 2 p. 242 | 1894 A. i., 

 T. Stebbing in: Bijdr. Dierk.. r. 17 p. 32 t. 6 | 1880 Acanthonotosoma i., D'ürban in: 

 Ann. nat. Hist., ser. 5 r. 6 p. 255 | 1887 A. i., H. .1. Hansen in: Vid. Meddel., ser. 4 r. 9 

 p. 127 j 1893 A.? i., A. Della Valle in: F. Fl. Neapel, f. 20 p. 676. 



Integument scabrous in parts. Peraeon dorsally broad. rounded, without 

 carina or processes. Pleon segments 1 — 3 with slight median carina. Head, 



