1910.] NATURAL SCIENCES OF PHILADELPHIA, 119 
flattened and tapering to the base, which is alittle gibbous and rounded. 
Its latter part is straightened and runs forward shortly beyond the 
preceding whorl, the upper wall descending slightly. Otherwise it is 
not noticeably contracted behind the aperture. The outer lip is 
narrowly expanded and revolute, and is lined within with a rather 
thin white callus. 
One living specimen in the lot is an albino, pure white with some 
bluish spots. 
The axial lamella is strongly developed; superior lamella variable, 
but usually strong and extending through the last half of the penultimate 
whorl. Basal lamella variable, usually wanting, but sometimes strong. 
Twenty specimens opened give the following data: 
Three lamellze: superior, axial and basal (15%)— 
Length 14, diam.4 mm.; whorls 125. 
73 14, ce 4 (73 73 123. 
GG ie ey a a a 2 
Two lamellz: superior and axial"(65%)— 
Length 14.8, diam. 4 mm.; whorls 133. 
‘< 14.5, Cee: ‘“ “ 130 
as 14, ce 4 cc “ 125. 
“ 14, 6th By Pea 6c 124. 
SSA BE Oe tela cd A ‘ pate rae (22, 
ee atege. 2 Se Qu 123. 
73 13.3, Coy yal ‘“ ‘“ 124. 
‘“ 13: COM YE ‘“ ‘“ iio Ss 
Ts 12. Tae | ‘ “ ie 
‘c 12, GP ALS ian se 6c Ute 
‘“ 12, Ca > Yt 0 ‘é 114. 
‘ 11.5, sae. “ rT 114. 
0 Pe aa eS ce 
One lamella: axial (20%)— 
Length 12, diam. 3.8 mm.; whorls 113. 
CL DOA gM Naty an es ee Yaa aie ae se 
i tile eet | Sal a tee) Ws 
OOTP cele an ¢f Sih! sath (spire broken). 
The above specimens were taken at random. 
Holospira arizonensis emigrans n. subsp. Pl. XI, figs. 5-8. 
The shell is in the average more slender than arizonensis, with more 
numerous whorls; striation slightly finer, and often extending weakly 
upon the smoother lower whorls; the last whorl has a broad contraction 
