470 MAZATLAN UNIVALVES 
the acuminate growth, continuity and delicacy of the zigzag 
pattern, and fineness of the labial teeth. In one specimen the 
labrum is finely corrugated within. Long. °72, long. spir. ‘3, 
lat. °3, div. 45°. 
Hab.—Mazatlan ; 3 dead sp. only ; Z’pool Col. 
Tablet 2185 contains a sp. tenanted by hermit crab. 
598. OLIVELLA PPETIOLITA, vur. AUREOCINOTA. 
P=Oliva petiolita, Ducl. in Chén. Ill. Conch. p. 5, pl. 1, f. 21, 22. 
Comp. O. mutica, Say, in Rve. Conch. Ic. pl. 29, f. 93, a, 6. (Non 
O. mutica, Ducl. in Chén. p. 6, pl. 2, f.5,6: var. f. 7, 8:— 
= Dactylidea mutica, H. & A. Ad. Gen. i. 146.) 
O. t. “O. mutice, Say,” simili, sed majore, spird acutiore ; 
infra suturam zond extus aured et intus purpurea cincta ; linets 
fusco-purpureis varie angulata, rarius undulata; callositate 
basali intensiore, magis declivi ; plicis columelle subobsoletis. 
As it is doubtful whether this shell be either the true 
O. petiolita or the true O. mutica, a name and diagnosis are 
added which may rank either as a variety or a species, accord- 
ing to further light. On comparing the Mazatlan shells with 
genuine W. Indian specimens from Dr. Cutting in the Bristol 
Museum, there scarcely appear grounds of specific separation ; 
the most evident being the infrasutural golden band, the basal 
fold rather more slanting, and the plaits fainter than in most, 
but not all of the Caribbzan shells. Long. '37, long. spir. °16, 
lat. °16, div. 50°. 
Hab.—(O. petiolita.) Mexico [Pubi], Duclos. —(O. mutica) 
Barbadoes, Dr. Cutting.—(O. aureocincta) Mazatlan; very 
rare; L’pool Col. 
Tablet 2186 contains 8 sp. exhibiting the principal varieties 
of pattern. 
599. OLIVELLA INconsFicua, OC. B. Ad. 
Oliva inconspicua, C. B. Ad. Pan. Shells, pp. 50, 304, no. 34. 
Comp. O. oryza, Lam. An. s. Vert. vol. x. p. 631, no. 62. 
This species was described by Prof. Adams from dead, 
immature specimens, apparently for geographical reasons. On 
comparing the only fresh adult found with O. oryza and its 
