316 Stenopleustes 



4. Gen. Stenopleustes 0. Sais 



1893 Stenopleustes, G. 0. Sars, Crust. Norway, v. 1 p. 354. 



Body sleuder, smootb, thin-skinned. Kostrum and post-antennal corners 

 little produced. Side-plates not very large. Antenna 1 slender, much longer 

 than antenna 2. Lips nearly as in Neopleustes (p. 311). Mandible, molar 

 powerful, compressed, palp moderate. Maxilla 1, inner plate with 1 seta. 

 Maxillipeds, inner plates rather broad, outer plates small, with a few hairs, 

 3"^ Joint of palp apically much produced. Gnathopods 1 and 2 imperfectly 

 subchelate, not strong. Peraeopods 1 — 5 rather slender. Telsou nearly as 

 in Neopleustes. 



2 species. 



Synopsis of species: 



Pleon smooth 1. S. malmgreni . p. 316 



Pleon nodiferous 2. S. nodifer . . p. 316 



1. S. malmgreni (Boeck) 1871 Amphithopsis m., A. Boeck in: Foih. Selsk. 

 Christian., 1870 p. 199 ] 1876 A. m., A. Boeck, Skand. Arkt. Amphip., v.2 p. 350 t. 23 

 f. 7 I 1893 Stenopleustes m., G. O. Sars. Crust. Norway, v. 1 p. 355 t. 125 f. 1 | 1893 

 Acanthozone longicaudata (part.), A. DellaValle in: F. Fl. Neapel, u 20 p 605. 



Pleon without nodules. Head, rostrum short. blunt, lateral corners angular. 

 Pleon Segment 3, postero-lateral corners quadrate. Eyes very large, reniform, 

 light red. Antenna 1, 1^* Joint subequal to 2*^ and 3*^ combined, flagellum 

 nearly 6 times as long as peduncle, 1^* Joint elongate. Antenna 2, ultiraate 

 Joint of peduncle longer than penultimate, flagellum longer than peduncle, 

 Guathopod 1, 5*^ Joint rather longer than oblong oval 6*^ palm very oblique, 

 spinöse. Gnathopod 2 rather larger, h^^ Joint rather shorter than 6**». Peraeo- 

 pods 3 — 5, 2*^ Joint large oval. Uropod 3, inner ramus 3 times as long 

 as peduncle, outer much the shorter, both spinöse. Telson triangulär oval. 

 Colour whitish, sometimes faintly carneous. L. 9 7 mm. 



Arctic Ocean, North -Atlantic, North -Sea and Skagerrak (Norway). Depth 

 150—282 m. 



2. S. nodifer (0. Sars) 1882 Amphithopsis nodifera, G. 0. Sars in: Forh. Selsk. 

 Christian., nr. 18 p. 103 t. 5 f. 6a — b | 1893 Stenopleustes nodifer , G.O.Sars, Crust. Norway, 

 V. 1 p. 356 t. 125 f. 2 ! 1895 S. n., A. O.Walker in: P. Liverp. biol. Soc, v. 9 p. 303 | 1893 

 Acanthozone nodifera, A. DellaValle in: F. Fl. Neapel, v.'20 p. 604 t. 59 f. 15. 



Pleon Segments 1 and 2 ending dorsally in pair of juxtaposed nodi- 

 form projections (often difficult to make out). Head, rosti'um a little produced, 

 lateral corners rounded. Pleon segment 3, postero-lateral corners somewhat 

 produced. Eyes large, reniform, dark red. Antenna 1, 1^* Joint rather longer 

 than 2^ and 3*^ combined. Gnathopods 1 and 2, palm rather shorter than 

 in S. malmgreni. Telson longer, ti-iangular with narrowly rounded apex. 

 Other points closely agreeing with S. malmgi'eni. Colour whitish, pellucid^ 

 speckled yellowish or brownish; peduncle of antenna 1 and uropods 1 — 3 

 generally dark brown (Sars); limbs and specially peraeon segments 4 — 6 

 speckled with dark red (Walker). L. Q 3—5 mm. 



North-Atlantic, North-Sea and Skagerrak (Norway, depth 56- 188 m; Great 

 Britain, depth 57 ni). 



