LIMAPONTIIDjE. 81 



Species of Elysia. 



australis, Quoy and Gaim. lobata, Gould. 



elegaus, Milne Edir. timida, Risso. 



fusca, Phil. viridis, Mont. 



Genus PLACOBRANCHUS, Van Hasselt. 



Body with two, large, semicircular, membranous expan- 

 sions, crossing on the back and forming a canal open at 

 both ends. Tentacles club-shaped, lobed at the end. 



Ex. P. ocellatus, Quoy and Gaimard, pi. 67, fig. 7. 



In M. Bang's figure of this genus the lateral expansions 

 appear to he extended, and the tentacles are short and 

 conical ; most probably, when at rest, the animal folds them 

 over the back, and thus forms the tubular canal described 

 by Van Hasselt. 



Species of Placohranchus. 

 ianthobaptus, Gould. ocellatus, Quoy and Gaim. 



Fam. LIMAPONTIID^. 



Body depressed. Tongue narrow; teeth in a single, 

 central series. Tentacles none, or simple, contractile. Gills 

 none external. 



In this group of slug-like forms the branchial appendages 

 are altogether absent, or represented only by simple lobes or 

 ridges on the sides of the body ; the tentacles are linear, and 

 not longitudinally folded as in Elysiidce, and the body is 

 depressed. In the genus Rhodope of Kolliker the Mol- 



