434 Maera 



10 



11 



{Body extremely slender — 9. 

 Body not extremely slender — 11. 



( Gnathopod 2, palm excavate near defining angle 8. M. hamigera . . . . p. 437 

 \ Gnathopod 2, palm not excavate — 10. 



j Peraeopod 5 shorter than peraeopod 4 . . . 9. M. tenella p. 438 



\ Peraeopod 5 not shcrter than peraeopod 4 • 10. M. loveni p. 438 



iPleon Segment 3, postero-lateral comers serrate 

 above and below, acutely produced ... 11. M. othonis p. 438 

 Pleon Segment 3, postei-o-lateral corners serrate 

 only above, quadrate 12. M. mastersii . . . . p. 439 



1. M. tenera 0. Sars 1876 Moera tenella, Maera t. (nou Gammarus tenellus 

 J. D. Dana 1852!), G. O. Sars in: Arch. Naturv. Kristian., v.2 p. 259, 271 | 1885 Maera 

 tenera,'^ G. 0. Sars in: Norske Nordhavs-Exp., ■;;. 6 Crust. I p. 177 1. 14 f. 7 | 1893 M. t., 

 A. Della Valle in: F. Fl. Neapel, t?.20 p. 724. 



Body very slender, almost cylindric, smooth. Head, lateral lobes 

 rounded, little promiuent. Side-plates very shallow, 1^* the deepest, rounded 

 in front, produced a little forward. Pleon segment 3, postero-lateral corners 

 quadrate. Eyes entirely wanting. Antenna 1 elongate, 1^ and 2^ joints subequal, 

 3"^ about Ys as long as 2*, flagellum shorter than peduncle, 16-jointed, accessory 

 flagellum 4-jointed. Antenna 2 of % length of antenna 1, ultimate Joint of 

 peduncle shorter than penultimate, flagellum shorter than peduncle, 8-jointed. 

 Gnathopod 1 small, 6*^ Joint not larger than 5*^. Gnathopod 2 powerful, 5*^ Joint 

 (in figure) broad and rather longer than broad, 6*^^ very large, almost quadrate, 

 twice as large as 5*^, setose, finger not very large. Peraeopods 1 — 5 very 

 slender, with scanty armature, 3"^ — 5*^ with linear 2*^ Joint, peraeopods 

 4 and 5 ^ elongate. üropods 1 — 3, rami slender, lanceolate. üropod 3 

 reaching little beyond the others. Telson very small, deeply incised. L. 

 10 mm. 



North-Atlantic (Storeggen [Norway]). Cold area, depth 785 m. 



2. M. quadrimana (Dana) 1853 & 55 Gammarus quadrimanus, J. D. Dana 

 in: U. S. expl. Exp., v.lSu p. 955 t. 65 f. 9 | 1862 Moera q., Bäte, Cat. Amphip. Brit. 

 Mus., p. 194 t. 35 f. 5 I ?1882 M. q., G. M. Thomson in: Tr. N. Zealand Inst., v. 14 p. 235 

 1. 17 f. 4 a, 4b I 1893 Maera truncatipes (part.), A. Della Valle in: F. Fl. Neapel, ü.20 p.725. 



Body slender, smooth. Side-plates 1 — 4 shallow, subquadrate. Pleon 

 segment 3, postero-lateral corners said to be dentate (Della Valle). Eyes 

 (in figure) small, rounded. Antenna 1, 1^* and 2^ joints long, subequal, 3*^ very 

 Short, flagellum rather shorter than peduncle, accessoiy flagellum rather 

 longer than half the primary. Antenna 2, peduncle shorter than in antenna 1, 

 flagellum very short. Gnathopod 1 small, 6**i Joint oblong, both 5*^ and 6*^ 

 widened distally. Gnathopod 2, 5*^ Joint small, cup-shaped, 6*^ very large, 

 widened to the palm, which lorms a somewhat obtuse angle with the bind 

 margin, is divided into 3 blunt teeth, and defined by a long, acute tooth, 

 separated from the others by a cavity (Thomson: front margin longer than 

 the bind margin ; 2 small teeth in place of the long defining tooth). Peraeo- 

 pods 1 and 2 very slender. Peraeopods 3—5, 2^ Joint moderately expanded 

 and produced downward, 4*^ Joint rather broad, produced, finger sharply 

 produced behind the short nail. Peraeopod 5 a little shorter or longer than 

 peraeopod 4. üropods 1 — 3 (in figure) reaching about equally f ar back. Uropod3, 

 rami straight, equal, in figure subacute, tipped with slender setae. üropod 2 



