354 TUERITID^. 



Bela decussata. 



Fig. 1S5. 



Shell oval, ash or flesh-colored, with twent\--five minute folds, and close re- 

 volving lines ; notch of the outer lip shallow. 



Pleurotoma decussata, CocxnocT, Bost. Joiirn. Xat. Hist. ii. 183, pi. 4, fig. 8. — Gould, 



Inv. 1st ed. 280, fig. 18.5. — De Kay, X. Y. Moll. 150, pi. 36, fig. 344. 

 Bcla decussata, Stimpsos, Check Lists, 5. 



Shell small, ovate, of an ash-white, or flesh-color, covered w^th 



remnants of an olive colored epidermis ; whorls five or six, convex, 



the lowest beino- two thirds the Icnirth of the shell, covered 



Fi" 623. , '" , . . . ^ 



"' with twenty-five to thirty inconspicnons folds or rilis, undu- 

 ^^ lated and obliqne in conformity to the outer lip. and vanish- 

 ^7 iiig on the convexity of the whorl ; lines of growth regular 

 B. ciecus- and distinct, and these, with numerous, elevated, revolving 

 threads, make a fine network over the whole shell ; spire 

 regularly sloping to an acute point ; suture well-marked, with a 

 slight shoulder near it on the whorls ; aperture half as long as the 

 shell, narrow, oval, terminating in a broad and very brief channel ; 

 outer lip sharp, with a shallow recess or notch, as it joins the whorl ; 

 pillar arched, flattened, and smooth ; operculum pear-shaped, with 

 the apex below, and the elements concentric. Length, seven twen- 

 tieths of an inch ; breadth, three twentieths of an inch ; divergence, 

 forty-eight degrees. 



Found in the stomachs of fishes, not unfrequently. Marblehead 

 {Haskell) ; Eastport {Cooper') ; Banks {Willis). 



This is not liable to be confounded with any shell of our coast, 

 except B. harpularia, to which it has a miniature resemblance. 

 But, besides being so much smaller, it is distinguished by the notch 

 at the posterior angle of the aperture, and by the network formed 

 by the more numerous and fainter folds, and revolving lines. The 

 color, which Mr. Couthouy makes a distinctive mark, is very nearly 

 the same. His specimens were less perfect and white. In my 

 freshest specimen there is a broad, lighter-colored band near the 

 top of the lower whorl. Pleurotoma reticulata, Brown ('•' Conchol- 

 ogy of Great Britain," «tc., pi. 48, figs. 29, 30), may, perhaps, be 

 intended to represent the same. 



