GASTROCOPTA, NORTH AMERICA, WEST INDIES. 29 



chology, 1878, p. 343. - - Pupa montanella COCKERELL, The 

 Journal of Concliology, Leeds, vi, 1889, p. 63; British Nat- 

 uralist, 1891, p. 101. Pupa curvidens GOULD, Invertebrata of 

 Massachusetts, 1841, p. 189, f. 120. Pupilla florida.no, BALL, 

 Proc. U. S. Nat. Mus., viii, 1885, p. 261, pi. 17, f. 11. Pupa 

 curvidens var. gracilis STERKI, Nautilus, iii, 1890, p. 119; 

 Land and Fresh- Water Mollusca in the Vicinity of New 

 Philadelphia, 1894, p. 5. 



This widely-spread species may be recognized by the small 

 size, spermaceti or bluish-white color and simple parietal 

 tooth, with lip-teeth arranged on a white callous rim. It is 

 most easily obtained by dirt or leaf sifting. It lives on 

 wooded hillsides or in well-drained groves among leaves in 

 the underbrush; also "is common among moss and grass in 

 forest and on open slopes." 



The variations in shape and teeth are shown in plates 4 

 and 5, figs. 1-41. PI. 3, figs. 2, 3, 5, and pi. 4, fig. 1, are 

 typical pentodon, which has 5 teeth. The parietal lamella "is 

 really composite, that is, composed of the parietal and the 

 angular, although the latter is generally quite small, a mere 

 appendage of the former. In many specimens of pentodon it 

 is quite distinct (see pi. 3, fig. 6; pi. 4, figs. 3, 12, 21, 27; pi. 

 5, fig. 32), and in some the whole lamella is even bifid, some- 

 what like that of B. holzingeri" (Sterki). More commonly, 

 and typically, the angular lamella is wanting, or so small 

 that it is not distinguishable from the parietal (pi. 3, fig. 2). 

 The columellar lamella descends spirally (pi. 3, fig. 5). 



PI. 4, figs. 1 to 8 are from Maine specimens, showing the 

 ordinary variations. The development of a crest behind the 

 lip varies a good deal, from weak to very strong, with all in- 

 tergrades. 



P. cincinnatiensis (pi. 5, fig. 35, a cotype) is merely a small 

 form of pentodon. It is described as having the "peristome 

 simple, heavily thickened near the margin, the callous ex- 

 tending over the parietal wall ; aperture contracted by five 

 prominent denticles, seated on the callous, one prominent on 

 the parietal wall, two on the columella, the lower being the 

 smaller of the two, and two on the outer portion of the peri- 



