ASTRA LITM. ^;> 



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

 -eral nucleus; outside convex, white, granuloM-, more or leae excava- 

 ted around the upper margin, excavated near t lie center; y<>uiiu r with 

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

 by a short straight rib. 



A. CUBANHM Phil., 1*4*. PI. 5r>, fiirs. 77, 78. 



Shell elevated-conic, imperforate, solid, whitisli or pale yellow; 

 whorls 7, upper two smooth by erosion, sutures moderately inn. 

 ed ; whorls flattened above, longitudinally coarsely plicate, nodulous 

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

 ber on the last whorl, cut about the middle by a few spiral impiv-s- 

 ed lines ; base slightly convex, concentrically lirate, and radiatdy 

 densely striate, the lira? about six in number, sometimes nodd-e; 

 aperture wide, subtrapezoidal ; columella arcuate, grooved slightly 

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

 cliately plicate cordon. Alt. 38, diam. :>."> mill. 



West Indies ; Tortugas (Simpson). 



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. (unerietuium, but separated by the more decidedly 

 granulate and ribbed operculum, which resembles closely that ot .1. 

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

 icanum, and more numerous than in A. olfersii. 



A. I'APFLLATUM Potiez et Michaud, 1838. PI. 52, figs. 14-17. 



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

 scurely banded, spire acute ; whorls 7, nearly flat, slight ly e.vavated in 

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

 oblique, slightly prominent above, at the periphery tuberculose ; last 

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

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

 line 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 Li' 



Operculum nearly like that of A. cubanum. 

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

 The species is nearly allied to A. cubanum, perhaps- identical 

 15 



