Metopa 173 



I Gnathopod 1 distinctly subchelate 13. M. leptocarpa . . p. 178 



\ Gnathopod 1 not distinctly subchelate — 14. 



j Anteunae 1 and 2 long — 15. 

 \ Antennae 1 and 2 not long — 17. 



{Peraeopods 4 and 5, 4th Joint narrow, scarcely 

 decurrent 14. M. longicornis . . p. 179 

 Peraeopods 4 and 5, 4th Joint decurrent, not 

 narrow — 16. 



f Side-plate 4 nearly as deep as broad 15. M. pusilla .... p. 179 



I Side-plate 4 not nearly as deep as broad ... 16. M. aeqmcornis . . p. 180 



j Gnathopod 2, palm serrate — 18. 

 \ Gnathopod 2, palm smooth — 19. 



J Gnathopod 2, palm irregularly serrate .... 17. M. borealis . . . . p. 180 

 \ Gnathopod 2, palm regularly serrate 18. M. rubrovittata . p. 180 



/ Grnathopod 2 strong 19. M. sölsbergi . . . p. 181 



^ \ Gnathopod 2 feeble — 20. 



(Body slender; gnathopod 2, 6th Joint oblong 

 triangulär 20. M. tenuimana . . p. 181 



20 



I x>o 



quadrangular 21. M. invalida . . . p. 182 



^ Body stout; gnathopod 2, 6tü Joint oblong 



1. M. esmarki Boeck 1872 M. e., A. Boeck in: Forh. Selsk. Christian., 1871 

 p. 47 I 1893 M. esmarkü, A. DellaValle in: F. Fl. Neapel, v. 20 p. 644. 



Back round. Side-plate 4 very large. Antenna 1 in d much, in 9 little 

 sh orter than antenna 2, 1^* Joint much longer than 2*^, flagellum 10- or 1 1-jointed. 

 Antenna 2, ultimate and penultimate joints of peduncle subequal, flagellum very 

 Short. Gnathopod 1 in d slender, 4*^1 Joint produced, öt'i wider and considerably 

 longer than the naiTOwly oval 6*^ which has no definite palm. Gnathopod 2 in d 

 robust, 5*^ Joint cup-shaped, 6*^ pow^erful, with a deep and wide cavity 

 between a stout process of the bind margin and a small tooth, over which 

 the finger curves to meet the process, leaving a small cavity between its 

 hinge and the tooth. Gnathopod 2 in Q with much smaller process and 

 cavity, the margin serrate above and below the small tooth. Peraeopods 1 — 5, 

 joints slender, except the 2"^ of peraeopod 5, which is almost broader than 

 deep, the 4**^ of peraeopod 3, which is not much expanded, and the 4**^ of 

 peraeopods 4 and 5, which is very much widened and overlaps all the next Joint. 

 Uropod 3, peduncle with 6 spines, longer than ramus. L. 9 4, d 5 mm. 



North-Pacific (California). 



2. M. robusta 0. Sars 1892 M. r., G. O. Sars, Crust. Norway, v. 1 p. 270 

 t. 96 f. 1. 



Body stout, integument very firm. Head, lateral corners angular. Side- 

 plate 4 nearly twice as large as 2*^ and 3'^ combined, lower margin very sinuous. 

 Pleon Segment 3, postero-lateral angles rather produced. p]yes round, bright 

 red. Antennae 1 and 2 subequal. Antenna 1, flagellum longer than peduncle, 

 14-joiuted. Antenna 2, ultimate and penultimate joints of peduncle subequal, 

 flagellum 9-jointed. Gnathopod 1, 2*^joint rather broad and lamellar, 4*^'forminga 

 broadly rounded setiferous lobe, 5*^ very narrow and elongated, rather tapering, 

 6*^ about half as long, linear, finger short, finely ciliated within. Gnathopod 2 

 powerful, as in M. norvegica (p. 177), the 4*i*and 5*^ joints both cup-shaped; 6*'» 

 subquadrate, but gradually expanded towards the slightly oblique, convex, in 

 part coarsely sen-ate, palm, which is defined by a strong tooth. Peraeopod 1 



