ürchomenella 81 



48. Geu. Orchomenella 0. Sars 



1871 Orchomene (part.) + Tryphosa (part.), A. Boeck in: Forh. Selsk. Christian., 

 1870 p. 114, 117 I 1890 & 95 Orchomenella (part.), G. ü. Sars, Crust. Norway, v. 1 p. 66; 

 p. 683 1894 0., T. Stebbing in: Eijdr. Dierk., v. 17 p. 6. 



Side-plates large. Antenna 1, accessorj flagellum moderately developed. 

 Antenua 2 in 9 little longer tbau antenna 1, in c? not greatly elongated. 

 Epistome little or not projecting beyond upper lip. Mouth-organs nearly as 

 in Orchomene (p. 44), molar of mandible rather stronger, outer plate of maxiila 1 

 more obliquely truncate, inner and outer plates of maxillipeds sborter and 

 palp longer. Gnathopods, peraeopods and uropod 3 in 9 as in Orchomene. 

 uropod 3 in d nearly the same as in Q , telson larger than in Orchomene, 

 oblong triangulär, cleft extending beyond the centi-e, scarcely dehiscent. 



5 species. 



Synopsis of species: 

 ( Epistome not at all prominent — 2. 

 ) Epistome rather prominent — 4. 



J Eyes wanting 1. O. laevis . . . . j). 81 



\ Eyes present — 3. 



\ Side-plate 5 scarcely produeed downward beliind . . 



) Side-plate f) produced downward behind 



j Side-plate 5 deeper than broad, produced downward 

 \ Side-plate 5 broader tlian deep, not produced . . . 



1. O. laevis Bonnier 1896 O.I., J. Bonnier in: Ann. Univ. Lyon, «/'.26 p. 617 

 t. 35 f. 5. 



Pleon Segment 4 with deep dorsal depression. Head, lateral corners 

 sharply produced. Pleon segment 3, postero-lateral corners strongly produced, 

 apparently subacute. Eyes entirely wanting. Antenua 1 in d short, 2*^ and 

 3<^ joints very short, flagellum without calceoli, with 11 joints, l^*notvery long, 

 sborter than accessory flagellum. Antenna 2 nearly as long as body, with 

 a calceolus on each Joint. Epistome with crest not projecting in front of 

 Upper lip. Lower lip, mandibular processes acute. Maxiila 1, ^^ Joint of 

 palp with 6 spines on apical margin. Maxiila 2 (in flg.), inner plate sborter 

 than outer. Maxillipeds, outer plates fully reaching end of palp's 2"^ Joint, inner 

 margin crenulate, apical carrying a spine and 4 setae. Gnathopod 1, 5**^ Joint 

 subequal to 6^'», 6*^ oblong, the short oblique palm defined by a spine at the 

 angle. Gnathopod 2, ö^'i Joint not nearly twice as long as the subchelate 6*^. 

 Peraeopods 1 and 2. finger longer than G^^^joint. Peraeopods 3 — 5 successively 

 sborter (text. but in flg. 4*^ the longest), 2*^ Joint oblong oval in peraeopods 3 

 and 4, much more expanded in peraeopod 5, very broad and longer than the 

 remaining joints combined. Uropods 1 and 2 short, rarai as long as peduncle; 

 uropod 3 much longer, inner ramus with 3 spines on inner margin, outer 

 rauch longer, 2-jointed, with 3 spines on outer margin. Telson deeply 

 cleft, with a pair of lateral and a pair of apical spines. L. 5 mm. 



Bay of Biscay. Depth 950 m. 



2. O. nanus (Kreyer) 1846 Anonyx n., Kreyer in: Xaturh. Tidsskr., ser. 2 

 r.2 p. 30 I 1846 A. n., Kreyer in: Voy. Nord, Crust. t. 17 f. 2a— t | ?1893 A. n. (part.), 

 A. DellaValle in: F. Fl. Neapel, «;. 20 p. 820 | 1871 Tryphosa «., A. Boeck in: Forh. 

 Selsk. Christian., 1870 p. 117 ] 1893 T. nana, J. Bonnier in: Bull. sei. France Belgique, 

 «7.24 p. 170, 191 t. 7 ! 1895 Orchomenella n. {Anonyx namus, laps. !), G. ü. Sars, Crust. 

 Norway, v. 1 p. 683 I 1882 Tryphosa ciliata, G. O. Sars in: Forh. Selsk. Christian., nr. 18 

 p. 81 t"3 f. 4 i 1891 Orchomenella c, G. 0. Sars, Crust. Norway, v. 1 p. 69 t. 25 f. 2. 



Das Tierreich. 21. Lief. : T. R. R. Stebbing, Amphipoda I. 6 



