172 Metopidae, Metopa 



j Peraeopods 4 and 5. 2fl Joint little or not at all 



2 I expanded 2. Gen. Metopella . . p. 182 



l Peraeopods 4 and 5, 2d Joint expauded — 3. 



Antenna 1 with rudinientary accessory flagellum 3. Gen. Metopoid.es . p. 185 

 itenna 1 without accessory flagellum .... 4, Gen. Proboloides . i). 187 



1. Gen. Metopa Boeck 



j Ant 

 \ Ant 



1871 Metopa (part.), A. Boeck in: Forh. Selsk. Christian., 1870 p. 140 | 1876 M., 

 A. Boeck, Skand. Arkt. Ampliip., v.2 p. 451 | 1892 M., G. 0. Sars, Oust. Norway, v.l 

 p. 248 I 1893 M., A. DellaValle in: F. Fl. Neapel, e. 20 p. 634. 



Relative proportions of anteunac 1 aud 2 vaiying. Lower lip with inner 

 lobes coalesced. Mandible. raohir wanting, palp small, 3^^ Joint very short. 

 Maxiila 1, palp 1-jointed. Maxillipeds (Fig. 44), inner plates coalesced alraost 

 to the'apices, outer plates wanting. Gnathopod 1 (Fig. 45) small, seldora 

 distinctly subchelate. Gnathopod 2 (Fig. 46) distinctly subchelate, usually 

 strong, often differing in the two sexes. Peraeopod 3, 2'^ Joint not expanded. 

 Peraeopod 4 usually, peraeopod 5 always, with 2'^ Joint expanded. üropod 3, 

 peduncle longer or shorter than the 2-jointed ramus. 



21 species. 



Synopsis of species: 



J Peraeopod 4, 2^ Joint not expanded 1. M. esniarki . . . . j). 173 



) Peraeopod 4, 2d Joint expanded — 2. 



( Side-plate 4, lower margin sinuous — 3. 



\ Side-plate 4, lower raargin not sinuous — 5. 



I Gnathopod 1, 2d Joint rather broad, lamellar . 2. M. robusta . . . . p. 173 

 I Gnathopod 1, 2d Joint not expanded — 4. 



i Peraeopod 5, 4thjointproducedstraightdo\vnward 3. M. sinuata .... p. 174 

 4 < Peraeopod 5, 4th Joint produced downward with 



l a curve 4. M. propinqua . . p. 174 



{Gnathopod 1, finger fringed with curved setae 

 or spines — 6. 

 Gnathopod 1, finger not fringed with curved setae 

 or spines — 7. 



I Antennae 1 and 2 short 5. M. palmata . . . . p. 174 



) Antennae 1 and 2 long 6. M. clypeata . . . p. 175 



Antennae 1 and 2 markedly unequal — 8. 

 Antennae 1 and 2 not markedly unequal — 13. 



Antenna 1 shorter than antenna 2 — 9. 

 Antenna 1 longer than antenna 2 — 10. 



J Animal small, with large eyes 7. M. alderii . . . . p. 175 



) Animal large, with small eyes 8. M. spectabilis . . p. 176 



j Gnathopod 2, palm not deeply incised — 11. 

 1 Gnathopod 2, palm deeply incised — 12. 



/ Gnathopod 1, 6th joint nearly linear 9. M. affinis . . . . p. 176 



\ Gnathopod 1, 6th joint rather broad 10. M. latimana . . . p. 177 



{Gnathopod 2, thumb-like process reaching beyond 

 the palm 11. M. norvegica . . . p. 177 

 Gnathopod 2, thumb-like process not reaching 

 beyond the palm 12. M. boeckii . . . . p. 178 



10 

 11 



12 



