272 MOLLUSCA. 
Distinct by the remarkable narrowness of the whorls, the height of the visible part 
of the middle ones being scarcely 4 of their diameter. 
9. Celocentrum fistulare. 
Cylindrella fistularis, Morelet, Test. Noviss. i. p. 10 (1849) '; Pfr. Monogr. Helic. Vivent. iii. 
p. 569°; Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, Cylindrella, p. 38, t. 4. figg. 21, 
22°, 
Celocentrum fistulare, Fisch. & Crosse, Miss. Scient. Mex., Mollusca, 1. p. 348, t. 15. figg. 12, 12a’; 
Strebel, Beitr. Mex. Land- und Siissw.-Conch. iv. p. 58, t. 6. fig. 2, t. 14. figg. 1a, B 
(columellar axis) ’. 
Cylindrella arctispira, Tristram, P. Z. S. 1863, p. 412 (nec Pfr.) °. 
Hab. N. Guatemata: forests of Peten (Morelet\*); Vera Paz (Salvin ®) ; Coban 
(Sarg °). 
The specimen from Vera Paz determined as Cylindrella arctispira by Tristram ® is 
now before me, and I am able to state that it belongs to C. fistulare, Morel. 
10. Celocentrum crosseanum. 
Cylindrella crosseana, Pfr. Journ. de Conch. xv. p. 437 (1867) *; Monogr. Helic, Vivent. vi. 
p. 878°; Novitat. Conch. p. 437, t. 97. figg. 26, 27°. 
Eucalodium crosseanum, Crosse & Fisch, Journ. de Conch. xviii. p. 22%. 
Celocentrum crosseanum, Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i, p. 351, t. 15. figg. 16, 
16a°; Strebel, Beitr. Mex. Land- und Siissw.-Conch. iv. p. 60, t. 6. figg. 1 a-d and 5, 
t. 14. figg. 4 and 7 a, B (columellar axis) °. | 
Hab. %. Mextco: Orizaba (Bottert!*); Cuautlatitlan, between Jico and Perote, N. of 
Orizaba (Dota Estefania ®). 
11. Celocentrum filicosta. 
Cylindrella fiicosta, Shuttleworth, Diagn. never Moll. i. p. 86 (Mittheil. der naturf. Ges. in 
Bern, 1852, p. 296) *; Pfr. Monogr. Helic. Vivent. iii. p. 573°; Martini & Chemnitz, Syst. 
Conch.-Cab. ed. 2, Cylindrella, p. 19, t. 2. fig. 80, and t. 8. figg. 9, 10°; Sowerby, in 
Reeve’s Conch. Icon. xx., Cylindrella, t. 12. fig. 107 *. 
Eucalodium filicosta, Crosse & Fisch. Journ. de Conch. xviii. p. 22 (1870) ’. 
Celocentrum filicosta, Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 352, t. 15. figg. 17, 
17 a (columellar axis) °; Strebel, Beitr. Mex. Land- und Siissw.-Conch. iv. p. 61, t. 5. 
fig. 14". 
Hab. EK. Mexico: Cordova (Jacot-Guillarmod and Sallé1—*). 
Obs.—Cylindrella aristispira (ear-spike), Sowerby, in Reeve’s Conch. Icon. xx., 
Cylindrella, t. 1. fig. 5, locality unknown, has much the appearance of a Celocentrum, 
but I cannot refer it to any of the above species. 
