PNEUMODERMID^. 41 



2. Spongiobranchia ELONGATA. 



Body very much elongated, fusiform, pointed behind, brown-violet ; 

 head narrow; mouth white, with long appendages ; fins round, 

 white, small ; gills white. 



Spongiobranchea elongata, UOrh. Voy. Am. Mer. Moll. 132, t. 9, 

 f. 8, 9. 



Hab. Atlantic Ocean. 



3. TRICHOCYCLUS. 



Head produced, conical, with two lateral tentacles. — Body elongate ; 

 fins 2, oblong, lateral, with a lanceolate intermediate lobe ; gills 

 in a ciliated ring round the middle of the abdomen, and with a 

 similar ring round the base of the head and on the hinder end of 

 the body. 



Trichocyclus, Eschsch. Isis, 1825, 735, t. 5, f. 4 ; Menke, Syn, ed. 

 2, 9; Gray, Syn, B. M. 1842, 86, 92; Proc. ZooL Soc. 1847, 

 204. 



1. Trichocvclus Dumerilii. 



Body oblong, cylindrical, truncate ; fins broad, rounded. Length 

 1 line. 



Trichocyclus Dumerilii, Eschsch. Isu, 1825, 735. 



Hab. South Sea. 



4. PELAGIA. 



Animal gelatinous, rough, transparent. — Body oval elongate, con- 

 tracted in the middle ; head indistinct, with two small tubercles ; 

 mouth hidden ; fins 2, lateral, at the contraction of the body ; 

 vent at the base of the right fin ; nerves very apparent. 



Pelagia, Quoy ^ Gaim. Voy. Astrol. ii. 392, 1832, not Peron Sr 

 Lesueur, 1809, nor Lamx. 1821; Menke, Zeitsch.f. Malak. 1844, 

 42. 



1. Pelagia alba. 



Body elongate, fusiform, white-netted, rough ; fins submedial, 

 rounded, striated. 



Pelagia alba, Quoy ^ Gaim. Voy. Astrol. 392, t. 27, f. 7—9. 

 Hab. 



E 3 



