54 



RANDOM NOTES ON NATURAL HISTORY. 



The Shell-Bearing Mollusca of Rhode 

 Island. 



BY HORACE F. CARPENTER. 



Chapter. XXX. 



Family Achatinellidse, three genera, 

 fourteen sub-genera, and about three hun- 

 dred and fift}' species of beautifully colored 

 shells, confined almost exclusively to the 

 Sandwich Islands. 



Family Cylindrellidse, four genera, seven- 

 teen sub-genera, and over two hundred 

 species, inhabits the West Indies and Trop- 

 ical America. 



Family Piipidae, consists of eight genera, 

 the largest of which, Clausilia, has seven 

 hundred species, none of which inhabit the 

 United States ; the next largest. Pupa, 

 with about four hundred species, distributed 

 among twenty sub-genera, is represented in 

 Rhode Island by two sub-genera, and the 

 genus Vertigo, with one hundred species, 

 by seven species in North America, six of 

 which are found in or near Rhode Island. 



Genus Pupa, Lam., 1801. 



Shell small, cylindrical or ovate-oblong ; 

 umbilicus slight ; plicate, striate or costel- 

 late, brown horn-color ; lip reflected, den- 

 tate or plicate within ; columella the same, 

 the extremities usually joined bv a raised 

 callus. 



The genus is divided into nineteen sub- 

 genera, onl}' two of which are represented 

 in the United States. They are Leucochila, 

 with eight species, and Pupilla, with seventj^- 

 seven. Both of these sub-genera contain 

 species which inhabit Rhode Island. 



102. Pupa (Leucochila) Armifera, Say. 



Shell cylindrical-oblong ; apex obtuse ; 

 whorls six or seven, smooth, convex ; aper- 

 ture small ; lip reflected, much thickened 

 within ; teeth four to five, the largest being 

 bifid, starting from the body whorl, at the 

 superior margin of the aperture ; umbilicus 

 perforated. Length, one-sixth of an inch ; 

 breadth, one-eighth. 



This is the largest species of the sub- 

 genus found in this country, and is easily 

 distinguished by its waxen white color, and 

 its peculiar bifid tooth. It has been quoted | 

 as abundant in the Middle and Western [ 

 States, extending as far east as Vermont, | 



where it has been found on the shores of 

 Lake Champlain. Mr. Thomson has found 

 it in Tiverton, R. I., near the shore of 

 StaflTord Lake. "Rare." 



103. Pupa (Leucochila) Contracta, Say. 



A widely distributed species, inhabiting 

 from Maine to Florida, and westward to 

 Iowa and Texas. It is not a very common 

 shell in New England, but is found under 

 the bark of decaying logs and stumps. 

 Morse says: " Found in beech groves under 

 bits of rotten bark." It has been found on 

 piles of old bricks. It has six whorls, 

 graduall^^ tapering to a not very obtuse 

 apex. It is of a whitish color, translucent 

 and distinctly umbilicated. The lip is 

 broadly reflected, and the aperture is nearly 

 closed by four strong teeth, one of which, 

 situated on the columella, is spoon shaped, 

 and contracts the mouth so that it resembles 

 a horse shoe in shape. The mouth is so 

 filled up by these teeth that it seems strange 

 how the animal can protrude its body at all 

 through the irregular and minute spaces be- 

 tween. Its length is one-tenth of an inch, 

 and its breadth one-twentieth. 



104. Pupa (Leucochila) Corticarica, Say. 



Shell cylindrical, white, shining ; apex 

 obtuse ; whorls five, convex with well im- 

 pressed sutures ; aperture small, sub-orbic- 

 ular ; lip reflected, white ; umbilicus mi- 

 nute. Length, one-tenth of an inch; 

 breadth, one-twenty-fifth. Distribution, 

 Maine to South Carolina, and from Wiscon- 

 sin to Mississippi. 



Described by Say in 1817 as Odostomia 

 corticarica, changed in 1819 to Pupa. The 

 character of the mouth of this species 

 varies in different individuals. Usually the 

 lip has a single tooth on the parietal wall, 

 near the centre, and a tooth-like enlarge- 

 ment near the umbilical termination of the 

 peristome ; sometimes there are two teeth 

 on the parietal wall ; in other specimens 

 there is a tooth, not in the centre, but a 

 little one side, and again some individuals 

 have no teeth at all. It is found under the 

 bark of dead trees near the ground. Mr. 

 George Hunt of this city found quite a 

 number of specimens in the crotch of a 

 dead oak tree some eight or ten feet from 

 the ground. 



