39 
Pupa placida. — Shell dextral, cylindric-conic, pale yellowish 
horn color ; apex whitish, obtuse ; whorls six and a half, some- 
what wrinkled ; suture moderately impressed ; aperture unarmed, 
longitudinally oval, truncate a little obliquely above by the 
penultimate volution ; columella so recurved as almost to conceal 
the umbilicus ; labrum, with the exception of the superior portion, 
appearing a little recurved when viewed in front, but when viewed 
in profile, this recurvature is hardly perceptible ; umbilicus very 
narrow. 
Length over three-tenths of an inch. Inhabits Massachusetts. 
For this shell I am indebted to Dr. T. W. Harris, of Milton, 
from w^hom I have received many interesting species of our more 
northern regions. At first view it might be mistaken for the P. 
marginata Noh.^ but it is quadruple the size, and the labrum is 
not reflected and thickened. 
Bulimus alterfatus. — Ovate conic, with alternate gray and 
brownish longitudinal vittse. Inhabits Mexico. 
Shell umbilicated, ovate-conic, with longitudinal lines, subequal^ 
gray and light brownish vittae; the brown is paler, almost ap- 
proaching in some instances a drab ; the white vittse consist of 
more or less confluent transverse, irregular lines, and small spots ; 
whorls about six, a little convex ; suture not profoundly impressed ; 
labrum (in some specimens) with a thickened line or rib on the 
inner submargin ; within white, with a pearlaceous tinge. 
Length one and one-fifth of an inch. Greatest breadth seven- 
tenths. This species appears to be not uncommon in Mexico, as 
many specimens were sent me by Mr. Maclure ; but from what 
particular locality I know not. 
B. UiSTDATus, Brug. — Occurs in some parts of Mexico. I 
found a specimen on the road from Vera Cruz to the city. The 
late Mr. Elliott, of Charleston, presented to me a Bulimus which I 
described under the name of reses ; but on comparing it to the 
present species, I think it may be considered as a variety ; it is 
rather less ventricose, the longitudinal lines are very slender and 
pale, and the transverse lines much more distinct. It inhabits 
trees in the south part of Florida. 
B. SERPERASTRus. — Elongate subovate, about six banded. 
Inhabits Mexico. Shell conic or elongate subovate, umbilicated ; 
whitish or white, with about six interrupted, more or less con- 
