266 APPENDIX. 



spicuous eyes. There are no capital or lateral lobes or cirrbi. 

 The sides of tbe foot are higb and ratber steep. On its caudal 

 portion there is a simple operculigerous lobe, bearing an ovate, 

 very thin, yellowish, paucispiral operculum. Tbe sole of tbe foot 

 is oblong, slightly truncate, with rounded angles in front and 

 rounded behind ; Avhen at rest it is subquadrate. These characters 

 accord best with, and do not differ materially from, those of the 

 genus Assiminia; nor is the shell so different in structure as to 

 prevent our slightly modifying the diagnosis of that group, so as 

 to admit more delicate forms than the Assiminea Grayana. They 

 do not accord exactly with those assigned to Paludinella, though 

 we think it probable that our shell is really the type of that 

 genus. We think it likely that in this form we have indications 

 of the true relations of Truncatella and Ol'ina, and that both those 

 genera should be placed among the Littorinidoe, and not beside 

 the Pyramidellidce. 



Assiminia littorea was found by us in crevices of fresh water 

 limestone, near high-water mark, at Whitecliff bay, in the Isle of 

 Wight. It was living in company with Conovulus hidentatus, in 

 situations similar to those in which we have gathered Otina otis. 

 Some years ago we' collected numbers of a very similar, if not 

 identical, little Assiminea (so styled at the time in our notes, on 

 account of the structure of the animal), under stones and weeds 

 at high water mark, at Toulon. The British specimens thrive in 

 confinement if kept in a jar, simply moistened with salt water. 



Mr. W. Thompson, of Weymouth, has obtained this very local 

 species from the estuary, near Portland, where he found it in com- 

 pany with Conovidi and Truncatellce, near high water mark, under 

 such stones only as were kept moist by a deepish layer of dead 

 zostera weed. 



In Plate MM. fig. 3, we have represented the animal. 



Vol. iii. p. 138. RissoA ventrosa. 



To the synonymy of this shell add Turbo ehnrneits, Adams, 

 Micros, pi. 14, f. 15, probably. 



We have given a delineation at Plate CXXXIII. f. 7, of a shell 

 which we have considered with some little doubt, a produced 

 imperforated variety of this species. It differs, however, from 



