162 PROCEEDINGS OF THE ACADEMY OF [March, 
Lymnea bulimoides cockerelli n. subsp. Figs. 13-17. 
Shell subglobose, pale yellowish-corneous, composed of 43 convex 
whorls which are finely striate but without spiral lines or malleation. 
Spire very short, last whorl and aperture very large. Aperture short- 
ovate, its length three-fifths to two-thirds that of the shell. Columella 
broadly expanded, not folded. Umbilicus large. 
Fig. 14. Fig. 15. Fig. 16. Fig. 17. 
Las Vegas, N. M. Arroyo Pecos. Ogalalla, Neb. 
Alt. 10 ao 8 S27 Bsa ge 8 9 mm. 
Diam. 7.2 6 622)" 30 6 1) 28 6.6% 
Aperture 6.7 ae 6 a =o 00, Ot, Osta 
New Mexico: Las Vegas (type locality, Miss Mary Cooper), and in the 
charcoal zone of the Pleistocene of Arroyo Pecos (T. D. A. Cockerell) ; 
near Farmington (George H. Pepper) ; Acama(Dr. E. Palmer). Colorado: 
Pool southeast of Denver (J. D. Putnam). Nebraska: Ozalalla (C. T. 
Simpson). Dakota: Lake Hermann (P. C. Truman). 
Fig. 19. 
This form differs from L. bulimoides and L. techella by-its more glo- 
bose shape and shorter spire, and so far as we have seen is readily separ- 
able from both. Figs. 138-15 represent the types from Las Vegas; 16, 17 
are larger shells from Farmington, sent by Mr. George H. Clapp. 
L. bulimoides sonomaensis Hemphill, from Sonoma county, California, 
approaches cockerelli, but differs by the more rapidly expanding last 
