MAZATLAN UNIVALVES 491 
vol. i. p. 330.—Desh. in Enc. Meth. vers. 11. p. 251, no. 1.— 
Blainv. Mal. i. 29, f.3 (teste Desh. : f. 23, test. C. B. Ad.)— 
Rve. Conch. Syst. vol. 2, p. 218, pl. 257, f. 1 (malé, C. B. 
Ad.J—Duel. in Chénu, Ill. Conch. pl. 5, f. 7, 8.— Kien. Icon. 
Conch. p.3, pl.1, f.1. (1, @ exel.)—B. M. Cat. D’Orb. Moll. 
p. 39, no. 342.—Mke. in Zeit. f. Mal. 1847, p. 182, no. 18.— 
C. B. Ad. Pan. Shells, p. 98, no. 102. 
Buecinum strombiforme, Wood, Ind. Test. Suppl. pl. 4, f. 18. 
Var. ?=Columbella gibbosa, Val. Rec. Obs. vol. ii. p. $31.— 
Chén. Ill. Conch. pl. 5, f. 5, 6.* 
Although Sowerby states that C. major is easily distinguished 
from this species, and says truly of picked specimens, yet 
C. major is so variable in its shape and size that it is not im- 
possible that this may be a permanent variety of that species 
as (v.v.) Kiener supposes. At the same time, as Deshayes 
remarks, the differences, though slight, acquire importance by 
their constancy. The present form is somewhat rounder in 
the spire; with the pattern developing streaks instead of 
spots; having the mouth more or less tinged with orange ; and 
also (what appears to be the most trustworthy character) with 
the radiating ridges in the epidermis, finely serrated by spiral 
lines all over, and not at the upper portion only, as in C. major. 
The size is more constant than in that species, adults being 
never found either sg large or so small. The opercula appear 
exactly like those of C. major, both in the normal and abnor-: 
mal conditions. The frequency of the latter, while the shell is 
quite perfect, shews that the animals are peculiarly lable 
(in both of the species) to pedal injuries. A broad specimen 
measures long. °95, long. spir. °28, lat. *62, div. 80°. 
A slender sp. ,, 1°01, “A sis sy, Obes ues meee 
Hab. — Acapulco, Humboldt & Bonpland.—Isle of Muerte, 
Cuming. — Payta, Peru, Fontaine, D’Orbigny. — Taboga,’ 
1 specimen, C. B. Adams.—Mazatlan, Melchers.—Do.; not 
uncommon among C. major; L’pool Col. 
Tablet 2335 contains 3 sp. young.—2336, 5-sp. broad form.— 
2337, 6 do. normal state.—2338, 2 do. acuminate.—2339, 4 sp. 
approaching C. major, yellow colour scarcely developed.—2340, 
4 sp. with opercula in situ, normal and abnormal, also loose 
opercula.—2341, 2 sp. shewing colour under epidermis. 
* As this shell is figured with a yellow mouth and light sp ots on the back, it is 
atone to say whether it is intended for a variety of OC, strombiformis or of 
» major, 
