39 



Pupa placida. — Shell dextral, cylindric-coiiic, 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 5 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 whom I have received many interesting species of our more 

 northern regions. At first view it might be mistaken for the P. 

 marginata, Jfob., but it is quadruple the size, and the labrum is 

 not reflected and thickened. 



BuLiMUS ALTERNATUS. — Ovate conic, with alternate gray and 

 brownish longitudinal vittae. Inhabits Mexico. 



Shell umbilicated, ovate-conic, with longitudinal lines, subequal, 

 gray and light brownish vittas ; the brown is paler, almost 

 approaching in some instances a drab ; the white vittse consists of 

 more or less confluent, transverse, irregular lines, and small spots ; 

 w^horls 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 perlaceous 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. UNDATUS, 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 on 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- 



