ASTEALIUM. 225 



Operculum (pi. 60, fig. 45) oval, light brown within, with sublat- 

 eral nucleus ; outside convex, white, granulose, more or less excava- 

 ted around the upper margin, excavated near the center ; young with 

 a stout curved central rib following the spiral, its ends connected 

 by a short straight rib. 



A. cuBANUM Phil., 1.S4S. PI. 56, figs. 77, 78. 



Shell elevated-conic, imperforate, solid, wdiitish or pale j'ellow ; 

 whorls 7, upper two smooth by erosion, sutures moderately impress- 

 ed ; whorls flattened above, longitudinally coarsely plicate, nodulous 

 on the ijeripheiy, the folds about twenty-two to twenty-eight in num- 

 ber on the last whorl, cut about the middle by a lew spiral impress- 

 ed lines ; base slightly convex, concentrically Urate, and radiately 

 densely striate, the lira3 about six in number, sometimes nodose ; 

 aperture wide, subtrapezoidal ; columella arcuate, grooved slightly 

 at position of umbilicus, bituberculate at base, surrounded by a ra- 

 diately plicate cordon. Alt. 38, diam. 35 mill. 



West Indies ; Tortugas (Simj^son). 



Operculum (pi. 60, fig. 48) with a strong central spiral granular 

 rib, with Its terminations joined by a short riblet, the interval be- 

 tween them deeply excavated. 



Allied to A. amerlcanum, but separated by the more decidedly 

 granulate and ribbed operculum, which resembles closely that of A. 

 olfersii. The peripheral nodes are less numerous than in A. amer- 

 ieanum, and more numerous than in A. olfersii. 



A. PAPiLLATUM Potiez et Michaud, 1838. PL 52, figs. 14-17. 



Shell conic, elevated, imperforate, solid greenish-olivaceous, ob- 

 scurely banded, spire acute ; wdiorls 7, nearly flat, slightly excavated in 

 the middle, finely obliquely striate and radiately costate, folds wdiite, 

 oblique, slightly prominent above, at. the peripher)^ tuberculose ; last 

 whorl carinated, with about fourteen short tubercles on the carina ; 

 base a little convex, radiately striate, with five concentric subnodose 

 lira? separated by very shallow grooves ; aperture transverse ; colu- 

 mella arcuate, bituberculate at the base ; umbilical tract bounded 

 by a plicate cordon. Alt. 25, diam. 29 mill. 



West Lidies. 



Operculum nearly like that of A. cuhanum. 



Figs. 16, 17 are from the original ones of Potiez and Michaud. 



The species is nearly allied to A. cuhanum, perhaps identical. 

 15 



