Actinacanthus, Atylidae 



327 



distally dilated, produced into 3 long processes, 2'^ Joint subequal to l'S 

 produced into 2 long processes, 3*^ Joint short, flagellum with 1^* Joint long, 

 longer than shaft of 1^* or 2^ Joint of peduncle. Antenna 2 with 2 large processes 

 on basal Joint, with 1 long and 2 short on antepenultimate, 2 long and 2 short 

 on peuultimate, 2 very small on ultimate Joint, which is longer than shaft 

 of penultiraate, flagellum rather longer than peduncle, with about 12 joints, 

 ^st veiy 1quo\ Mandible, spines of spine-row extremely uuequal, 1*^ Joint 

 of palp with tooth-like process, which seems to be movable, 3'^ Joint rather 

 longer than 2^, spinöse. Gnathopod 1 (Fig. 75), 2^ Joint the tbickest part 

 of the limb, 5^^ Joint stouter and much longer than 6^^^ which 

 is about 5 times as long as its greatest breadth, tapering to 

 minute oblique spinöse palm, finger very small. with tooth and 



Fif^. 74. Section tlirough peiaeoii segment 3. 



Fig. 74—76. A. tricarinatus. 



Fig. 75. Fig. 76. 



Gnathopod 1. Gnathopod 2. 



slender nail overlapping palm. Gnathopod 2 (Fig. 76) rather similar to 

 gnathopod 1, but much longer, 5^^ Joint not thicker than 6*^^ but 3 times 

 as long, 6^1* of uniform widtb. otherwise nearly as in gnathopod 1, palm 

 less spinöse. Peraeopods 1 — 5 with finger short, broad, spinulose. Peraeo- 

 pods 3 — 5, 2"^ Joint with 4 longitudinal ridges, below overlapping 3*^ Joint with 

 rounded lobe. 3*^ — 6*^^ joints carinate in front, 4*^'' aud 5*'' sharply decurrent. 

 Peraeopod 5 rather longer than peraeopod 4. Uropods 1 — 3, peduncle 

 Channelled above, rami equal. lanceolate, in uropod 1 rather shorter than 

 peduncle, in uropod 2 a little longer, in uropod 3 much longer. Telson 

 rather louger than broad, somewhat boat-shaped, broad distal margin convex. 

 L. about 16 mm. 



Southern Indiaii Ocean (Heard Island). Dejjth 282 m. 



25. Farn. Atylidae 



1865 Subfam. Atylina (part.), W. Lilljeborg in : X. Acta Soc. Upsal., ser. 3 v. 6 

 nr. 1 p. 18 I 1876 Subfam. Atylinae (part.), A. Boeck, Skand. Arkt. Amphip., v.2 p.320{ 

 1882 Atylidae, G. 0. Sars in: Forh. Selsk. Christian., nr. 18 p. 26 | 1888 Ä., T. Stebbing 

 in: Eep. Voy. Challenger, v. 29 p. 899. 



Body strongly compressed. carinate. Pleon segments 5 and 6 coalesced. 

 Antenna 1, accessory flagellum rudimentary or absent. Upper lip rounded. 



