300 CCELOCENTRUM, HOLOSPIRA. 



Var. TOWNSENDI Pilsbry & Cockerell, n. v. Vol. xvi, pi. 11, 



figs. 85, 86. 



Shell rimate, not perforate, cylindric, the upper fourth 

 rather rapidly tapering, gray-white, rather thin. Surface 

 lusterless, sculptured with rather coarse rib-striae, crowded, 

 and about as wide as their intervals. There are about 3 stri 

 to a millim. on the last whorl; about four on the middle 

 whorls. Whorls convex, the last very shortly free in front, 

 rounded below, the baso-peripheral keel barely indicated, not 

 raised. Aperture nearly circular, oblique, the peristome con- 

 tinuous, slightly expanded, very narrowly reflexed, whitish. 

 Columella straight. Axis a small transparent white tube with 

 white obliqi-e lines; noticeably swollen in each whorl; within 

 the last three whorls bearing at its base an acute spiral 

 lamella, 2y% whorls long. Length 31, diam. 9.5 mm. ; whorls 

 8%; longest (oblique) axis of aperture 7.7, width 7.4 mm. 



Western Mexico: Cualata, state of Colima (Prof. C. H. T. 

 Townsend, July, 1902). 



This species tapers less above than most of those known. 

 The sculpture is very much coarser than in A. liebmanni or 

 dalli, about as in strebeli, but the riblets are more crowded. 

 The internal lamella is longer than in any other species 

 known. Soft anatomy described above. 



A. recticosta is a somewhat larger form, and tapers more 

 gradually. In townsendi the last 5 whorls are of equal diam- 

 eter, forming a cylinder, only the first three whorls tapering. 

 The penult whorl is 3.5 mm. wide, from suture to suture, in 

 front. There is no such basal angle as is described for A. rec- 

 ticosta,-&n.d the rib-striae continue undiminished on the base. 



* Genus CCELOCENTRUM C. & F. 

 CCELOCENTRUM PISTULARE (Morel.). See p. 41. 



Another synonym is C. acutispira Pfr., Paetel, Catalog, ii, 

 p. 245 (1889), based upon C. arctispira Tristram; or rather, 

 it is an error for that name. 



Genus HOLOSPIRA v. Mart. 

 HOLOSPIRA COCKERELLI Dall. 



" Shell small, pupiform, blunt- tipped, with two smooth 



