MELANIAD^E. 87 



Foot broadly obovate, obtuse, compressed, evi- 

 dently of two distinct laminae, the lower projecting 

 beyond the upper, and separated from it by an accu- 

 rately defined line; above fuscous, beneath olivaceous, 

 shaded with cinereous ; tentacles very short and obtuse, 

 fuscous, eyes at their tips ; muzzle porrect, not truly 

 proboscidiform, deeply notched in front, fuscous, 

 strongly annulated ; the edge of the lips paler : on 

 each side is a groove running backwards from the 

 base of the tentacula. 



Shell about J inch long, ovate, solid, bright, shining, 

 liver-brown, with a conical spire, and slightly impressed 

 suture. The axis is imperforated. Operculum horny, 

 ovate, black-brown. 



Very like the small Littorince, but more solid, and 

 differs in the animal; it is curious that so abun- 

 dant a shell should have been overlooked by Mon- 

 tagu and his correspondents. 



There may be noticed two marine species, some- 

 times found with the former. 



1 . Littorina anatina. 



Paludina anatina. Drap., Michaud, Alder, Mag. 

 Zool. and Bot. ii. 116. 



Sometimes found in the marshes at Greenwich, 

 with the Assiminia Grayana. The shell is ovate, 

 perforated, thin, transparent; the whorles are ven- 

 tricose, rounded, and the mouth ovate ; the operculum 

 is horny, brown. It is like Bithinia ventricosa, but 

 smaller and shorter, and has a horny spiral opercu- 

 lum, like the periwinkle ; the peristome is continued ; 

 the shell is often covered with green Alga. 



