70 .EOLIDIDjE. 



Genus GELLINA, Gray. 



Tentacles linear, retractile, with infundibuliforin sheaths ; 

 forehead simple. Gills smooth, simple, arranged in a single 

 row on each side of the back. 



Ex. G. affmis, D'Orbigny, pi. 65, fig. 6. 



In this genus the gills, instead of being muricated, are 

 simple and ovate, and number about five on each side; the 

 funnel-shaped sheaths of the tentacles are large, and the ten- 

 tacles themselves linear and subulate. 



Earn. jEOLIDIDjE. 



Tongue narrow ; teeth in a single central series ; jaws 

 horny. Tentacles subulate, simple, rarely ringed, contrac- 

 tile. Gills superficial, fusiform or branched, on the sides of 

 the back. Vent lateral. 



In the family of iEolids the curious tentacular sheaths, 

 which are present in many of the other tribes of Nudi- 

 branchs, appear to be altogether wanting; the orifices of 

 the generative system and vent are situated at the right side, 

 and the gills, usually papillose, are arranged in rows along 

 the sides of the back. 



Sub-fam. GLAUCIN^. 



Gills papillose, in groups. Foot rudimentary. 



In this section, which comprises but few genera, the foot 

 is undeveloped, and the animals are oceanic in their habits ; 

 they are possibly predaceous, and are generally of a blue 

 colour. 



