16 MOLLUSCA. 
There is reason to think that the shell described by Mr. Lea, under 
the name of S. aperta, is the same as this; and that really, it was 
brought by Mr. Nuttall from the Sandwich Islands, instead of from 
Oregon. It is one of the forms peculiar to those islands, whereas 
nothing similar has been found on the American continent. 
The Ambrette fragile of Souleyet, figured in the Voyage of the 
Bonite, pl. 28, f. 18-20, is also apparently the same as this, though 
the representation is not good. 
Figure 14, the aperture; 14 a, the spire; 14 4, the profile of the 
shell, magnified; 14 c, natural size. 
SUCCINEA CEPULLA (Gould). 
Testa parva, tenuissima, pellucida, nitida, succineo-virens, rotundato- 
elliptica, depressa, sinistrorsum rotundata, dextrorsum declivis, longi- 
tudinaliter striata et liris inequalibus volventibus arata: spira feré 
nulla, anfractibus duobus cum dimidio : apertura amplissima, ovals, 
ad basim late rotundata, ad columellam arcuata, leviter plicata ; intus 
metallica. 
Succinea cepulla, Goutp; Proceed. Boston Soc. Nat. Hist., 1. 182. 
Nov. 1846. Expedition Shells, 27. 
ANIMAL not observed. 
SHELL depressed, nearly elliptical, remarkably broad posteriorly, the 
back rounded on the columellar side, and shelving, rather than 
rounded towards the outer lip: very thin and transparent, shining, 
amber-coloured. Surface marked with rather coarse and irregular 
lines of growth, and with coarse, shallow, and distant revolving fur- 
rows. Spire very minute; whorls two and a half, the last composing 
nearly the whole shell; suture well marked ; body of the shell beneath 
very small. Aperture very large, the lip making a remarkable sweep 
outwards, at its posterior portion, and broadly rounded at base; colu- 
mellar portion delicate, slightly folded. The interior has a metallic 
lustre. 
