24 VIVIPARA. 
Length 13-5, diam. 10 mill. 
Alexandria, La. 
Smaller than V. Troostiana, of different form 
and darker color. Mr. Binney considers the 
two identical, but they appear to me to be 
quite distinct. Ihave never seen any speci- 
mens of either except those in Mr. Lea’s 
cabinet. 
11. VIVIPARA PONDEROSA, Say. 
Hald., p. 18, t. iv. 
Plate 14, fig. 4. Plate 15, fig. 6. 
This species inhabits from Ohio to Iowa, 
and southward to Alabama. I have figured 
(fig. 4) an Alabama specimen as representing 
the var. A mentioned by Haldeman. V. regu- 
laris, Lea, is undoubtedly the young of this 
species; my figure (fig. 6) is drawn from one 
of Mr. Lea’s types. 
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