276 MOLLUSCA. 
shell, the greatest diameter being in the tenth whorl (at about one-third of the whole 
length, as seen from above), the following whorls diminishing remarkably in diameter, 
and the under-edge of some of them projecting a little over the following whorl. 
Fischer and Crosse’s figure of H. gealei (op. cit. t. 17. fig. 7) resembles it somewhat in 
outline, but is not so strikingly swollen above and wants the vertical coste. I give 
here a copy of the original figure published by me in 1865 1. 
2. Holospira tryoni. 
Cylindrella tryoni, Pfr. in Journ. de Conch. xv. p. 488 (1867) *; Monogr. Helic. Vivent. vi. p. 390°; 
Novitat. Conch. iii. p. 483, t. 97. figg. 5-7 °. 
Holospira tryoni, Crosse & Fisch. Journ. de Conch. xviii. pp. 14, 24, t. 5. fig. 5 (jaw) (1870) *. 
Bostrichocentrum tryoni, Strebel, Beitr. Mex. Land- und Siissw.-Conch. iv. p. 81, t. 5. fig. 3 (second 
figure), t. 14. figg. 13 (columellar axis), 16 4, B (aperture) °*. 
Holospira gealei (H. Ad.), Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 333, t. 17. figg. 7, 
7a, b, and t. 16. fig. 5 (jaw) °. 
Hab. CuxtraL Mexico: Matamoros Izucar, in the State of Puebla, on a species of 
cactus (Boucard®); Puebla 1~4. 
Var. gealei. 
Cylindrella (Holospira) gealei, H. Adams, P. Z. 8. 1872, p. 18, t. 3. fig. 19"; Pfr. Monogr. Helic. 
Vivent. viii. p. 447°. 
Holospira tryoni, Fisch. & Crosse, loc. cit. p. 331, t. 17. figg. 6, 6 a-c’. 
Bostrichocentrum tryoni, Strebel, loc. cit. t. 5. fig. 3 (first figure) ”. 
Hab. Centrat Mexico: State of Puebla, from a dealer 1°; ? Matamoros Izucar °. 
S. Centra, Mexico: Putla, in the State of Oaxaca’. 
Var. appressa, Ni. 
Holospira tryoni, var. 8, Fisch. & Crosse, loc. cit. p. 331”. 
Hab. CentraL Mexico: Matamoros Izucar !. 
The two varieties are probably nothing more than individual variations. 
H. tryoni and H. gealei, according to the original figures given by Pfeiffer and 
H. Adams, appear to differ chiefly in the shape of the shell—broadly ovate for 
H. tryont, and longer and exactly cylindrical in the middle in H. gealei. But the 
proportion of the diameter to the length of the shell in the figures does not in either 
case accord with the measurements given by the author. Pfeiffer, for H. tryoni, gives 
length 134 millim. and diameter 43 millim., the diameter, therefore, being one-third 
of the length; but the largest diameter, as well as that of the penultimate whorl, is 
considerably more than one-third the length. In H. Adams’s figure of H. gealei the 
diameter. if reduced to natural size, is a little less than five, not 54 times the length, 
as stated in the description. Either his figured specimen was not the same as that 
