22 GASTROCOPTA, NORTH AMERICA, WEST INDIES. 



G. contracta is the most specialized species of Albinula, 

 and has no near relatives among known forms, either recent 

 or fossil. The European Tertiary species are more nearly 

 related to armifera than to contracta. 



2. G-ASTROCOPTA CONTRACTA (Say). PL 2, figs. 9, 10, 11, 12. 



The shell is rimate, ovate-conic, tapering from the last 

 whorl to the obtuse apex, bluish-milky or spermaceti-colored, 

 imperfectly transparent, glossy, marked with fine growth- 

 striae. Whorls 5%, very convex, the last half of the last 

 whorl straightened, pinched at the base, impressed over the 

 lower palatal plica, and on both sides of a low rounded ridge 

 which stands a short distance behind the peristome (fig. 11). 

 Aperture rounded- triangular, almost closed by large teeth. 

 Angulo-parietal lamella joining the lip, angularly bent to the 

 right near the middle, then abruptly becoming much lower 

 and bent inward (pi. 2, fig. 9). Columellar lamella large, 

 thin, very deeply placed, subvertical, the upper end curving 

 forward (fig. 12). A subvertical callous stands in front of it, 

 near the margin (fig. 12). 



Palatal plicae two, connected by a low callous, the lower 

 one obtuse, transverse, more deeply placed and larger than 

 the tuberculif orm upper plica. Peristome thin, well-expanded, 

 continuous. 



Length 2.5, diam. 1.4 mm. 



Length 2.3, diam. 1.3 mm. 



Eastern United States and Canada: Maine, Ontario and 

 Manitoba, south to Miami, Florida, and Vera Cruz, Mexico; 

 Jamaica. Type locality, Oeeoquan, Virginia. 



Pupa contracta SAY, Journal of the Acad. Nat. Sci. Phila., 

 ii, p. 374, 1822. C. B. ADAMS, Contrib. to Conch., no. 9, p. 

 184 (Jamaica). PFEIFFER, Monographia Hel. Viv., ii, 358; 

 vi, 327; viii, 397. BINNEY, Terrestrial Mollusks, v, p. 207, 

 pi. 70, f. 2. Bifidaria contracta (Say), PILSBRY, Nautilus, 

 xi, 1898, p. 117. WALKER, Occ. Pap. Mus. Zool. Univ. Mich., 

 no. 15, 1915, pp. 9-11. Pupa deltostoma Charpentier, KUES- 

 TER, Syst. Conch. Cabinet, Pupa, 1852, p. 181, pi. 21, f. 17-19. 

 ? Pupa nebraskana W. G. BINNEY, in Warren's Prelim. 



