Orchestia 



531 



Gnathopod 2 in cj, finger without a strong tooth — 4. 

 Gnathopod 2 in (5, finger with a strong tooth — 5. 

 Peraeopod 5 in adult (5, »th joint as broad as long, 



6th straight 2. O. gammarellus . p. 532 



Peraeopod 5 in adult c5, 5tli joint longer than broad, 



6tli curved 3 



O. chevreuxi 

 O. montagui 

 O. tucurauna 



9 

 10 

 11 



12 



13 

 14 



15 



16 

 17 



18 



19 



20 



Gnathopod 2 in cj, tooth of finger central ... 4. 

 Gnathopod 2 in (5, tooth of finger close to hinge 5. 

 Gnathopod 1 in (5, 4*^1 Joint with apical process — 7. 

 Gnathopod 1 in (J, 4tli joint without apical 



process — • 8. 

 Gnathopod 2 in c5, palm with two excavatious 

 Gnathopod 2 in cj, palm smoothly convex . . 

 Body Segments acquiring transverse dorsal ridges — 

 Eody Segments not acquiring dorsal ridges — 10 

 Gnathopod 2 in cJ, palm slightly oblique . 

 Gnathopod 2 in (J, palm very oblique . . 

 Peraeopod 5, 2d joint scarcely expanded . 

 Peraeopod 5, 2d Joint regularly expanded — 11 

 Gnathopod 2 in (5, palm deeply concave . 

 Gnathopod 2 in (5, palm not deeply concave — 12 

 Gnathopod 2 in (5", palm with strong tooth near 



finger-hinge — 13. 

 Gnathopod 2 in c5, palm without tooth near finger- 

 hinge — 14. 

 Gnathopod 2 in (5, palm with one strong tooth . 

 Gnathopod 2 in cj, palm with two teeth .... 

 Gnathopod 2 in <5, 6tli Joint narrowing to the palm 

 Gnathopod 2 in (5, 6tli joint not narrowing to the 



palm — 15. 

 Gnathopod 1 in cj, öth joint much longer than 6tli — 16. 

 Gnathopod 1 in c?, 5th joint not much longer 



than 6th — 17. 



Side-pate 5 deep 15. O. pickeringii 



Side-plate 5 not deep ". . 16. O. nitida . . 



Gnathopod 2 in (5, palm very oblique — 18. 

 Gnathopod 2 in cj, palm not very oblique — 19. 

 Gnathopod 1 in <5, finger covering whole apex of 



6tli Joint 17. O. humicola. 



Gnathopod 1 in (J, finger not covering whole apex 



of 6tli Joint 18. O. floresiana 



Antenna 2 slender, flagellum cylindric 19. O. grillus . . 



Antenna 2 stout, flagellum flattened — 20. 



Gnathopod 1 in (5, 6tli Joint with prominent process 20, O. platensis 

 Gnathopod 1 in (J, 6th joint without prominent 



process 21. O. sulensoni 



p. 533 

 p. 533 

 p.534 



p.5B8 

 p.539 



p.539 



p.539 

 p. 540 



p.540 

 p.541 



1. O. mediterranea A. Costa 1857 0. m., A. Costa in: Mem. Acc. Napoli, 

 v.l p. 181 I 1866 O.m., Cam. Heller in: Denk. Ak. Wien, v.26ii p. 4 1. 1 f. 7 | 1881 

 0. m., Nebeski in: Arb. Inst. Wien, v.S p. 143 | 1895 O.m., Chevreux in: K,ev. biol. 

 Nord France, v.l p. 158 | 1899 0. m., T. Scott in: ßep. Fish. Board Scotl., v.ll p. 264 

 1. 13 f. 9— 11 I 1857 O.laevis, Bäte in: Ann. nat. Hist., ser. 2 i;. 19 p. 136 | 1862 0. 

 trigonocJieirus, Bäte, Cat. Amphip. Brit. Mus., p. 26 t. 4 f. 6 | 1893 0. chilensis (part.), 

 0. spinimana, A. Della Valle in: F, Fl. Neapel, v.20 p. 498 t. 2 f. 8; 1. 15 f. 31— 38; 

 p.l29, 248, 941. 



