Onisimus 2& 



14. Gea. Onisimus Boeck 



1871 Onisimvs (part.), A. Boeck in: Forli. Selsk. Christian., 1870 p. 111 1894 

 0., T. Stebbing in: Eijdr. Dierk., t;. 17 p. 10 | 1872 & 76 Onesimus (part.), A. Boeck, Skand. 

 Arkt. Amphip., v.l t.4— 6; v.2 p. 161 | 1891 0., G. 0. Sars, Crust. Norway, v. l p. 104 ; 

 1893 0., J. Bonnier in: Bull. sei. France Belgique, u 24 p. 174 | 1893 Pseudalibrotu» 

 (Sp. un.: P. littoralis) (part.), A. Della Valle in: F. Fl. Neapel, «;.20 p. 798. 



Body rather robust. Side-plates of moderate size, pleon segmeDt 3 

 with postero-lateral corners distinctly produced. Antenna 1, peduncle stout,^ 

 2^ and 3^ joints very short, both autennae in ö longer than in Q and provided 

 with distinct calceoli. F]pistome very slightly prominent, detined from upper 

 lip by a distinct sinus. Mandible, molar rather strong, palp not large, set 

 well forward. Maxiila 1, inner plate with 2 setae, outer broad, obliquely 

 truncate, with 1 1 spines, several (5 — 8) spine-teeth on palp. Maxiila 2, 

 outer plate broader and much louger than inner. Maxillipeds noraial, outer 

 plates crenulate. carry ing ou rounded apex 1 — 3 spines, not reaching beyond 

 2** Joint of slender, rather elongate palp. Gnathopod 1 subchelate, not very 

 robust, 6^11 Joint narrowly oblong, little or not at all longer than 5*^. 

 Gnathopod 2, 6*'' Joint uniformly uarrow or distally widened. Peraeopods 3—5 

 rather short and robust. Cropod 3 short, outer ramus with small 2^ Joint, 

 and sometimes setiferous. Telson short and broad, never deeply incised,. 

 sometimes entire. 



8 species. 



Synopsis of species: 



I Eyes large; telson incised — 2. 



) Eyes small; telson not incised — 5. 



I Gnathopod 1, 6th Joint longer than 5tli ... 1. O. ed'wardsii p. 25 



\ Gnathopod 1, 6th Joint subequal to ö^^ — 3. 



I Peraeopods 3 — 5, 4th Joint very robnst ... 2. O. plautus p. 26 



) Peraeopods 3—5, 4th Joint not very robust — 4. 



j Pleon segment 1, antero-lateral angles uncinate 3. O. normani p. 2& 



4 '. Pleon segment 1, antero-lateral angles not 



I uncinate 4. O. turgidus p. 26 



, I Telson apically truncate 5. O. brevicaudatus . . p. 27 



) Telson apically indented — 6. 



j Gnathopod 2, palm widened, emarginate ... 6. O. caricus p. 27 



6 I Gnathopod 2, palm not widened, nor emargi- 

 I nate — 7. 



[ Eyes iraperfect 7. O. leucopis p. 28 



) Eyes normal 8. O. affinis p. 28 



1. O. edwardsii (Krwyer) 1846 Anonyx e., Krwyer in: Naturh. Tidsskr., ser. 2 

 v.2 p. 1,41 I 1846 A.e., Kreyer in: Voy. Nord, Crust. t. 16 f . 1 \ 1893 A. e. (part.), 

 A. Della Valle in: F. Fl. Neapel, f. 20 p. 828 | 1871 Onisimtis e., A. Boeck in: Forh. 

 Selsk. Christian., 1870 p. 113! 1894 O.e., T. Stebbing in: Bijdr. Dierk., u 17 p. 10 | 

 1872 & 76 Onesimus e., A. Boeck, Skand, Arkt. Amphip., v.l t. 6 f. 4; v.2 p. 167 | 1891 

 0. e., G. 0. Sars. Crust. Norway, v. I p. 105 t. 36 f. 1. 



Head, lateral angles but slightly projecting, evenly rounded. Side-plate 1 

 rather expauded below, 4^*^ with hinder expansion short, obtusely truncated. 

 Pleon segment 3, postero-lateral angles produced to a narrow slightly upturned 

 lobe. Eyes rather large, oblong oval, slightly expanding below, bright red. 



