128 THE NAUTILUS. 



surface very slightly striated, shining ; whorls six, gradually increasing, 

 with the suture rather deep between the upper, less so between the 

 lower whorls; the last whorl moderately ascending at the aperture, 

 rather rounded at the base, slightly expanded near the aperture, with 

 an impression over the inferior palatal fold ; aperture rather oval, 

 truncated above, margins well everted, the palatal somewhat more 

 curved than the columellar, the two connected by a thin callus; 

 lamellae and folds four, subequal ; angulo-parietal appearing almost 

 simple, inclined toward the columella ; columellar horizontal, rather 

 short and strong, palatals rather short and stout, in normal position, 

 the inferior somewhat larger and more remote from the margin ; size : 

 alt. 2.4 to 2.8, diam. 1 3; apert. alt. 1.0 mm. 



Hab.: Capitan Mts., Lincoln Co., New Mexico. Over a hundred 

 good, fresh specimens were collected by Rev. E. H. Ashmun. 



In size, shape and color, our species has much resemblance to 

 Bif. contracta Say, but the aperture, with its lamellae and folds, is 

 very different, as is at once apparent from the description. Bif. 

 quadridentata rather ranges with Bif. pilsbryana, which, however 

 is very much smaller, usually has a basal lamella and whose angulo- 

 parietal shows hardly its being complex. 



BIP. HORDEACELLA Pils. var. PARVIDENS, n. Quite small, apex more 

 acute than in typical examples, and outline more obovoid ; peristome 

 rather abruptly but narrowy everted ; lamella? and folds small, es. 

 pecially so the upper palatal, often being a mere trace ; basal absent 

 or very small; color pale horn ; alt. 1.5 to 2 mm. Jerome, Arizona, 

 a good number of specimens, collected by Rev. E. H. Ash mum. 



PUPA (PiJPlLLA) SONORANA, n. sp. Shell perforate-rimate, cylin- 

 drical, apex obtuse, rounded ; color brownish horn ; surface finely 

 striated-rugulose, more coarsely so near the aperture ; whorls 6, grad- 

 ually increasing; suture rather deep; the jast whorl comparatively 

 small, compressed in its inferior part, the base narrow, almost keeled ; 

 near the aperture a high, sharp bulging filled with a strong whitish 

 callus, shining through the shell ; a narrow, deep constriction in front 

 of it, and an impression over the palatal fold; aperture rather small ; 

 margins abruptly but rather narrowly everted ; lamellae and fold&-3, 

 white; parietal rather deep seated, long, spiral ; columellar perpen- 

 dicular (along the columella), lamellar ; palatal (the inferior) rather 

 strong, often with a thread-like prolongation inward. Size : alt. 2.ti, 

 diam. 1.3. 



