278 MOLLUSCA. 
from the slender cylindrical form ¢ to the more distinct claviform, with the largest 
diameter near the upper end, ¢ (fig. 13), and the more abbreviate and bulky pupiform, 
q (fig. 15). The sculpture, colour, form, and size of the aperture are similar in all the 
specimens received. The apical cone formed by the 6-7 terminal whorls varies 
somewhat in its elevation, but is always well distinct from the cylindrical main part of 
the shell. The opening of the umbilicus is also variable in size, see fige. 10 and 15. 
For the young state, see fig. 16. 
This species somewhat resembles H. gealei, H. Adams, in shape, one or two indi- 
viduals agreeing even tolerably well with the author's figure of it; but the whorls 
are considerably higher comparatively in H. gealei than they are in H. claviformis. 
The main part of the shell is formed by 8 whorls in H. gealei and by 12 in H. claviformis ; 
the total number of whorls in A. gealei is 12-13, in H. claviformis 17-19. The 
aperture is also comparatively larger and the costulation of the last whorl in 
H. claviformis is not mentioned in the description of H. gealet. H. pilocerei, var. , 
Fisch. & Crosse, Miss. Scient. Mex., Mollusca, p. 329, t. 12. figg. 5, 5a, 6, from 
‘“‘ Mexico,” without nearer indication of locality, perhaps belongs to the same species ; 
but in the figure the upper part of the shell appears to be less tectiform. 
4. Holospira microstoma. 
Cylindrella microstoma, Pfr. P. Z.S. 1861, p. 27*; Monogr. Helic. Vivent. vi. p. 390 °. 
Holospira microstoma, Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 337, t. 17. figg. 9, 9a’. 
Hab. * Mexico 3. 
Near H. claviformis, but apparently distinct by the triangular aperture and the keel 
on the base of the last whorl; the upper part of the shell is also less regularly 
tectiform (H. claviformis in this respect being more like the following species), and 
the apex is not so papillary and prominent. 
5. Holospira pilocerei. 
Cylindrella pilocerei, Pfr. Symbole Hist. Helic. i. p. 47 (1841); Philippi, in Abbild. neuer Conch. 
1. p. 183, Cylindrella, t. 1. fig. 7*, and iii. p. 5, Cylindrella, t. 3. figg. 7, 8°; Monogr. 
Helic. Vivent. ii. p. 382°; and Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, Cylindrelia, 
p. 61, t. 6. figg. 32, 33°. 
Holospira pilocerei, Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 329°; Strebel, Beitr. 
Mex. Land- und Siissw.-Conch. iv. p. 82, t. 5. fig. 17, . 
Hab. CuntraL Mexico: Cuautla de las Amilpas, in the State of Puebla *, on the 
cactoid plant Pilocereus senilis (Hegewisch -") ; Mexico, without nearer indication 
of locality (Liebmann 2-*). 
* The locality is probably in the State of Morelos, and not in Puebla as stated. 
