470 MAZATLA^ 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. 



Hob. Mazatlan ; 3 dead sp. only ; L'pool Col. 

 Tablet 2185 contains a sp. tenanted by hermit crab. 



598. OLIVELLA PPETIOLITA, var. AUEEOCINCTA. 



?=Oliva petiolita, Duel, in Chen. III. Conch, p. 5, pi. 1, f. 21, 22. 

 Comp. O. mutica, Say, in Rve. Conch. Ic. pi. 29, f. 93, a, b. (Non 

 O. mutica, Duel, in Chen. p. 6, pi. 2, f. 5, 6 : var. f. 7, 8 : 

 = Dactylidea mutica, H. fy A. Ad. Gen. i. 146.) 

 O. t. "O. mutica, Sayii," simili, sed majore, spird acutiore ; 

 infra suturam zond extus aured et intus purpured cinctd ; lineis 

 fusco-purpureis varie angulatd, rarius undulatd; callositate 

 basali intensiore, magis declivi ; plicis columella 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 Caribbean shells. Long. *37, long. spir. *16, 

 lat. '16, div. 50. 



ITab. (O. petiolita.) Mexico [?ubi], 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, C. 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 



