GENUS FIROLA. 3 



Description of six new species of the genus Fir o la, ob» 

 served by Messrs, Le Sueur and Peron in the Mediter- 

 ranean Sea, in the months of March and Jpril^ 1809 

 % C. J. Le Sueur. With a Plate. 



MOLLUSCA PTEROPODEAf. 



Character, Body free; furnished widi fins for swim- 

 ming; head distinct. 



A. .Pteropodes naked. 



Character, Destitute of a gelatinous^ horny, or cal- 

 careous shell. 



^ No Tentacula. 

 Genus. — Firola. 



Char. Jaws horny; eyes two; fins 1, 2, 3; branchia 

 plumose^ floating freely beneath the body, and grouped 

 with the heart, around an oblong nucleus at the base of 

 the tail. 



The body is elongated, cylindrical, of a gelatinous, 

 diaphanous consistence, and of a pale colour. Tail dis- 

 tinguished from it by a groove, one fourth the length of the 

 body, compressed, more or less carinated, and laterally 

 serrated, terminated by a lobed fin, and sometimes with a 

 moniliform, elongated appendage. Eyes composed of a 

 brilliant hyaline globule, supported by a small peduncle, 

 which arises from a black concave or convex cup, placed 

 at the junction of the rostrum with the body. Several 

 small gelatinous points, before and above the eyes, serv- 

 ing probably to assist in retaining th^ molluscous prey in 



t Vrd. Anna!, d-j MudeVim d'JWfct, Kjtt. T. U jhdlO^ If 



