56 STERKIA. 



side (figs. 11, 12). Aperture about as wide as long, the outer 

 lip biarcuate, the upper arc shorter and more convex, with 

 a narrower lip than the lower. Angular lamella joining the 

 outer lip, thin, high and nearly straight. Parietal lamella 

 shorter, crescentic, the concavity towards the columella, high 

 and bent outward in the middle, tapering towards both ends, 

 reaching forward to a point opposite the middle of the an- 

 gular lamella. Columellar lamella consisting of a rather low, 

 horizontal portion curving into a shorter vertical portion 

 descending on the axis, and a less conspicuous but longer 

 branch ascending the axis (figs. 5, 12). The upper palatal 

 fold is rather deeply placed, a high, thin lamina about one- 

 fourth of a whorl long (seen below on the right in fig. 6). 

 The lower palatal fold is oblique, below the inner end of the 

 upper. There is a thin, short suprapalatal fold, not far 

 within, at the lower edge of the sinulus. The peristome is 

 expanded and reflected, pale brown or gray. 



Length 1.95; diam. 0.85 mm. 



Length 1.6, diam. 0.75 mm. 



Lower California: bank of San Tomas River (type loc. ; 

 Hemphill) ; Point Abreogos (Hemphill, 105486 USNM) ; En- 

 senada de Todos Santos, under decaying Mesembryanthemum 

 aquilaterale (C. R. Orcutt). California: around San Diego 

 (Orcutt) ; False Bay, Asher Station, in drift (S. S. Berry) ; 

 Mesa near Grantville, under prickly pear stems, and Pacific 

 Beach (Orcutt). Waterman canyon, San Bernardino Co. r 

 common (Berry). 



Pupa hemphttli STERKI, Nautilus, iv, July 1890, p. 27; 

 Aug. 1890, p. 39, pi. 1, f. 6. BINNEY, 4th Supplement to 

 Terr. Moll., vol. v, 1892, p. 192, f . a, b, c. Bifidaria hemp- 

 KilU BERRY, Nautilus, xxx, 1916, pp. 38, 83. Pupa calamitosa 

 part, PILSBRY, Nautilus, iii, p. 61, pi. 1, f . 6 ; Proc. A. N. S. 

 Phila., 1889, p. 411, pi. 12, f. 17. 



This minute species is much more complex in structure 

 than S. calamitosa, with which it occurs in the Lower Cali- 

 fornian stations. The extremes of size are represented in one 

 of the lots from False Bay, near San Diego, 1.6 and 2.05 mm. 

 long. 



