56 cymbuliidtE. 



Shell gelatlno-cartilaginous, oblong, slipper-shaped, cover- 

 ed with a thin scarcely visible membrane ; mouth elongate, 

 truncated in front. 



Ex. 0. proboscidea, Peron and Lesueur, pi. 6, fig. 7. 



There are three species of this genus known ; the shells 

 are slipper-shaped and variously spined, and of a firm gela- 

 tinous consistence. During the day they must occasionally 

 descend to considerable depths, one having been brought 

 up attached to the thermometer of a sounding-line during 

 the voyage of Her Majesty's ship " Samarang," from one 

 hundred and fifty fathoms in the South Atlantic. 



Species of Cymhidia. 



ovata, Quoy and Gaim. radiata, Quay and Gaini. 



proboscidea, Pero?! andLesueur. 



Genus EURIBIA, Rang. 



Animal globular ; wings two, horizontal, opposite, on 

 each side of the mouth, and with a small intermediate 

 lobe. 



Shell cartilaginous or membranous, thin, transparent, re- 

 gular, shaped like a hood ; mouth round, spread out. 



Ex. E. Gaudichaudii, Eydoux and Souleyet^ pi. 6, 

 fig. 8. 



The shell of this beautiful little Pteropod is membranous 

 and hemispherical, and the intermediate lobe of the animal 

 small and triangular : three species only appear to be 

 known. M. D'Orbigny, who never met with this genus, 

 imagines it to be the carapace of some crustacean. 



