HOLOSPIRA. O77 
from which the measurements were taken, or one of them is very inexact. Fischer 
and Crosse, on the contrary, figure under the name JZ. gealei (fig. 7) a broadly ovate 
shell, resembling Pfeiffer’s H. tryoni, and for H. tryont a cylindrical one, resembling 
H. Adams’s H. gealei, I should suppose that the figures had been exchanged by 
inadvertence, but in the text also H. gealei is said to be “proportionellement plus 
courte et plus renflée que la plupart de ses congénéres.” An explanation of these 
difficulties may be found in Strebel’s work, he giving the exact measurements of nine 
full-grown specimens, showing that the proportion of the diameter to the length of 
the shell varies from 1: 3 to 1: 2, the proportion of the aperture to the whole length 
about 1: 33 to 1:43, and the number of whorls from 114 to 154. The absolutely 
longer specimens are comparatively narrower, 7. ¢. they are less involute, but the 
difference in cubital measurement is not so great as seems at first sight. Probably 
these are only individual variations and not even local varieties, as also Fischer and 
Crosse’s var. 8 (appressa); but, for the present, I prefer to give in the Comparative 
‘Table of the species the characters according to the original descriptions and figures. 
As regards the sculpture, the original figures given by H. Adams and Pfeiffer do not 
show such a difference as would be supposed from Adams describing it as “ oblique 
striata” and Pfeiffer ‘‘ subtilissime striatula”; moreover, Fischer and Crosse do not 
attach importance to it. Adams’s definition “ anfr. supernis subangulatis’’ leads me 
to suppose that in some individuals the edge of the preceding whorls may project over 
the following ones, as in H. imbricata. 
The genus Bostrichocentrum was founded by Strebel on the fact that the spiral lamella 
was wanting within the second and third whorls before the last; but he himself states 
that this is also sometimes rudimentary in the species of Holospira (loc. cit. p. 82). 
8. Holospira claviformis, sp.n. (Tab. XVI. figg. 10-16.) 
Cylindrella piloceri, Sowerby, in Reeve’s Conch. Icon. xx., Cylindrella, t. 6. fig. 48 (nec Pfr.) °. 
Testa clavato-cylindrica, arctispira, peranguste perforata, solida, levissime oblique striatula, albida ; anfr. 17 -19, 
primi 2 flavidi, leaves, subglobosi, apice papillari, sequentes 5-6 celerius crescentes conulum humilem 
spire: formantes, ulteriores 12-13 diametro subsequales vel paulatim decrescentes testam clavato-cylindricam 
constituentes, sutura leviter impressa, ultimus humilis, costulis verticalibus subirregularibus sculptus, 
infra rotundatus, non ascendens, antice breviter protractus, hic supra complanatus et obtuse angulatus ; 
apertura subverticalis, quadrato-circularis, peristomate undique breviter expanso, albo. 
a. Long. 192, diam. anfr. penult. 4, diam. max. 53, apert. long. 3, lat. 3 millim. 
b. 29 19, 39 39 5, 29 6, 99 3, 29 3 99 
C. 99 19, 29 39 43, 99 5; 29 3, 29 3 2% 
d. 99 18, 29 99 43, 99 6, 99 3, 29 3 
é. 29 17, 39 29 43, 99 535 99 3, bf 3 
f. 29 16, 99 99 43, 99 5, 99 3, 29 3 39 
g- 99 16, 99 99 5, 29 6 
Hab. 8.W. Mexico: Amula near Tixtla, in the State of Guerrero (H. H. Smith). 
A large number of individuals, showing a considerable range of individual variation, 
