26 ANISOSPIRA. 



ish-fleshy ; whorls 7 to 8, internal lamella strong and 

 flat, 2 whorls long. A. liebmanni. 



II. Shell solid and strong, with moderately spaced rib-stria- 

 tion; flesh- tinted or pinkish; interna] pillar weakly 

 spiral, a blunt cord encircling its base within the penulti- 

 mate whorl. A. strebeli. 



A. HYALINA (Pfeiffer). PL 10, figs. 18, 19, 20, 21. 



Shell rimate, truncate, ovate-oblong, suddenly tapering 

 above, rather thin, diaphanous, hyaline. Whorls 10, a little 

 convex, narrow, subequal, subarcuately delicately rib-striate, 

 the last whorl shortly built forward, subangular above, obso- 

 letely compressed at the base. Aperture subvertical ; sub- 

 circular. Peristome free throughout, narrowly expanded. 

 Length 37, diam. 12, aperture length 9, width 8 mm. ; width 

 of middle whorl 3% mm. (Pfr.). 



South-central and southeastern Mexico: Oaxaca (Deppe), 

 probably Tabasco or Chiapa (Ghiesbreght). 



Cylindrella hyalina PFR. in Philippi, Abbild. u. Beschreib. 

 ii, p. 47, pi. 2, f. 2 (1847) ; Monogr. ii, 369; iii, 564; iv, 692; 

 vi, 359; viii, 425; Conch. Cab., Cylindrella, p. 8, pi. 1, f. 13, 

 14. _ v . MART., Malak. Blatt. xii, p. 14 (1865). SOWERBY, 

 Conch. Icon, xx, pi. 12, f. IW.Eucalodium hyalinum Pfr., 

 FISCHER & CROSSE, Moll. Mex. i, p. 388, pi. 15, f. 9, 9a. v. 

 MART., Biol. Centr. Amer., Moll., p. 266. Anisospira liyalina 

 Pfr., STREBEL, Beitr. Mex. Land- und Siissw.-Conch., iv, p. 79, 

 pi. 13, f. 16. 



The number of whorls varies somewhat, as more or fewer 

 of the narrow ones at the summit are retained, there being 

 sometimes as many as 13. It is distinguished from A. lieb- 

 manni by the greater number of whorls retained by the adult 

 shell, and the pale color. A. dalli is a closely related form, 

 which may eventually prove varietally related to liyalina. 



A. DALLI (v. Martens). PL 10, figs. 28, 29; pi. 1, fig. 12. 



" Shell thin, white, solid, opaque, decollated, the rejected 

 spire having 14 whorls, and the remainder of the shell from 

 71/0 to 9 whorls; apex of the young shell blunt, slightly dome- 

 shaped, the nepionic shell smooth or faintly transversely 



