GASTROCOPTA, NORTH AMERICA, WEST INDIES. 25 



is a primitive feature; otherwise the lamellae are rather 

 highly specialized. 



3. GASTROCOPTA HOLZINGERI (Sterki). PI. 2, figs. 4, 5, 6. 



" Shell narrowly perforated, turreted-cylindrical, vitreous 

 (or whitish), very minutely striate, shining; apex rather 

 pointed, whorls 5, regularly increasing, well rounded, espec- 

 ially the upper ones, the last somewhat narrowed and a little 

 ascending towards the aperture, compressed at the base but 

 not carinated, at some distance from the outer margin pro- 

 vided with an oblique, rather prominent, acute crest corres- 

 ponding in direction to the lines of growth, extending from 

 the base to the suture, formed by a whitish callosity; behind 

 the crest the whorl is flattened, and corresponding to the 

 lower palatal lamella, impressed. Aperture lateral, scarcely 

 oblique, relatively small, inverted subovate, with a slight sinus 

 at the upper part of the outer wall, margins approximated; 

 peristome moderately reflected; lamellae 6: one parietal, 

 rather long, very high, in its middle part curved outward, 

 towards the aperture bifurcated, the outer branch [angular 

 lamella] reaching the parietal wall; one columellar, longitu- 

 dinal, rather high, its upper end turning in nearly a right 

 angle towards the aperture, but not reaching the margin; 

 basal exactly at the base, short, high, dentiform; 3 in the 

 outer wall, viz. : the lower palatal long, ending in the callous, 

 highest about its middle ; the upper short, rather high on the 

 callous; above the upper one a suprapalatal, quite small, 

 dentiform, nearer the margin. Length 1.7, diam. 0.8 mm." 

 (Sterki), 



United States and Canada: Ontario and western New 

 York to Helena, Montana, south to Illinois, Kansas, and 

 Albuquerque and Mesilla, New Mexico. 



Pupa holzingeri STERKI, Nautilus, iii, August, 1889, pp. 37, 

 96, 119 ; Proc. A. N. S. Phila. for 1889, p. 414, pi. 12, f. 4-7. 

 BINNEY, 3d Suppl. to Terr. Moll., v, p. 93, text figure. 

 WALKER, Nautilus, v, p. 93 (Put-in-Bay Island, Lake Erie) ; 

 Occ. Pap. Mus. Zool. Univ. Mich., Nov. 15, 1915, pp. 4-9 (San 

 Miguel Co., N. M.). PILSBRY, Nautilus, xiv, p. 83. Bifidaria 



