472 MAZATLAN UNIVALVES 
f. 25.—Ducl. Monogr. Ol. pl. 1, f. 3, 4.—Rve. Conch. Ic. 
pl. 29, f. 91. 
Olivella zonalis, H. & A. Ad. Gren.i. 146. 
The O. mutica, as figured by Duclos, more nearly resembles 
this than No. 598. It is distinguished in colour by two distinct 
purple brown bands on the back, with a deep stain on the 
parietal and another on the basal callosity. The diffused hue 
is light or dark, with the same variation on the spire, and 
yellowish below the suture. Spire more or less acuminated. 
Mouth very open. Columella as it were excavated, smooth ; 
with one sharp, winding plait, bounding the siphonal notch. 
Long. °32, long. spir. °138, lat. °15, div. 50°, 
Hab.—Acapuleo, Humboldt & Bonpland.— Mazatlan ; ex- 
tremely rare; L’pool Col. 
Tablet 2198 contains 3 specimens varying in colour. 
Genus AGARONIA, Gray. 
Zool. Beech. Voy. 1839, p. 131.—H. & A. Ad. Gen. vol.i. p. 142. 
Hiatula, Swains.—Oliva, pars, auct. 
602. AGARONIA TESTACEA, Lam. 
Oliva testacea, Zam. in Ann. Mus. vol. xvi. 1810, p. 324, 
no. 51:—An. s. Vert. vol. x. p. 627, no. 51.—Val. in Humb. 
Ree. Obs. vol. ii. p. 334.—Ducl. in Chénu Conch. Ill. pl. 3, 
f. 17,18, (f. 19, 20, excl., teste C. B. Ad.)—Rve. Conch. Lc. 
pl. 18, f.36.—Mke. in Zeit. f. Mal. 1851, p. 25, no. 108.— 
O. B. Ad. Pan. Shells, no. 38, p. 54. 
Agaronia testacea, H. & A. Ad. pee i. 142, 
=Oliva hiatula, pars, Ducl. Mon. Oliv. pl. 3, f. 15, 16.—Non 
Lam. An. s. Vert. vol. x. p. 627, no. 52. 
Agaronia hiatula, [ Gray, non] Lam. Zool. Beech. Voy. p. 182. 
Having very carefully examined many hundreds of Mazatlan 
specimens, and compared them with a series sent from the 
Gambia by Chief Justice Rankin,* and also with the Bordeaux 
fossils assigned to O. hiatula by Deshayes and Duclos, it would 
appear that’ the judgment of Lamarck can be maintained 
* Of this valuable and very reliable collection, which I had an opportunity 
of examining on its first arrival, the principal part is to be found incorporated in 
the general Museum of the Bristol Institution. 
