ANISOSPIRA. 27 



striated, subsequent whorls to the fifth subcylindric, the fifth 

 slightly constricted, the spire very slowly increases in diameter 

 until the decollation is reached; the first four whorls after 

 the nucleus are conspicuously, elegantly, transversely ribbed, 

 the riblets nearly straight, with subequal interspaces. Be- 

 yond the constriction the riblets are less conspicuous and more 

 crowded and more oblique, and so continue evenly over the 

 adult shell where the suture is distinct but not deep, the form 

 somewhat fusoid, the basal whorl slightly contracted and sub- 

 angulate at the periphery, the umbilicus closed and the aper- 

 ture suborbicular and slightly reflected. The axis is mode- 

 rately stout and twisted, with a single plait on the pillar, 

 anteriorly, in the last and penultimate whorls, not however 

 visible from the aperture, much as in A. liebmanni Pfeiffer 

 (pi. 11, fig. 7). Length of decollate spire, 21 mm.; of decol- 

 lated shell, 29 mm. ; maximum diameter of shell, 10 mm. ; of 

 decollation, 6 mm." (Dall.). 



Huilotepec, State of Oaxaca (E. \V. Nelson). 



Anisospira strebeli DALL., Proc. U. S. Nat. Mus. xix, p. 353, 

 pi. 33, f. 7, 8 (Jan. 27, 1897) ; not of Pfeffer. Eucalodium 

 dalli v. MART., Biol. Centr. Amer., Moll., p. 633 (Feb. 1901). 



" This species is shorter and more slender than A. hyalina 

 Pfeiffer, which has always one and sometimes two more 

 whorls. It is of a whitish, not a pinkish tint, and the decol- 

 lated portion of the spire is more cylindrical than in A. hya- 

 lina, which has a proportionally larger and more trumpet- 

 like mouth. A. liebmanni is larger, stouter, of a brownish 

 yellow color, and has a whorl less than the present species " 

 (Dall). 



Ball's original figures are copied on plate 10. Figs. 12 of 

 plate 1, and fig. 7 of pi. 11, represent a specimen of the ori- 

 ginal lot in the collection of the Academy. It has 8 whorls, 

 and measures, length 29, diam. 10 mm. The columellar la- 

 mella is very close to the base, and is shorter and much less 

 prominent than in A. liebmanni. I have some doubts as to 

 the distinctness of this species from A. hyalina, but I have 

 not been able to compare specimens of the latter, which seems 

 to differ chiefly in retaining more whorls in the adult state. 



