GENUS BUCCINUM. 19 



* 19. BUCCINUM CALLOSUM, WOOD. The Callous Buccinum. 



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(Collect. MASS.) CHEMN. vign. 40, fig. 2. 



PI. VI, fig. 18 and 19. 



B. testa elongata, cylindriformi, laevi, nitida atro-cinerea ; spira elongatA, 

 acuta, basi cuj usque anfractus cingulitera, albida spadiceftque ; apertura 

 ovaliformi, dilatata, fulvescente; columella callosa, Isevi, arcuata, fulva. 



Shell elongated, cylindrical, the whole external surface 

 smooth, shining, of a coffee and milk color; spire elongated, 

 pointed, composed of six whirls not convex ; each whirl is 

 covered between the sutures with a layer of matter, which 

 assumes at the base a chestnut-color ; this layer is much thicker 

 upon the lowest whirl, and is continued, enlarging itself, to 

 the left lip, where it forms a large semicircular callosity, of a 

 deep chestnut-color, bordered with white. Each of the whirls 

 of the spire is likewise separated from the others by a fawn- 

 colored line, which is delineated a little below each suture. 

 The aperture is ovate, of a pale fawn-color, dilated towards 

 the middle, strongly emarginated at its base. The columella' 

 is arcuated, callous, fawn-colored and smooth ; the callosity of 

 the columella is oblique, thick, furrowed, much shorter than 

 the right lip ; from its lower part, a stria stretches out, which 

 is directed obliquely upon the back of the shell, to its termina- 

 tion at the anterior angle of the right lip, which is sharp. 



Length 20 lines. Width 8 lines. 

 Inhabits 



The BUCCINUM callosum is easily distinguished from the other 

 species ; its cylindrical form, and the layer of calcareous matter 

 which covers the whirls of the spire, characterize it with preci- 

 sion. In the collection of Prince Massena is found a variety 

 of this species which is of a nankin yellow, assuming a deeper 

 tint upon the sutures. The interior, in this specimen, is whitish ; 

 the edge of a bright yellow ; the columella callosity is of a dull 

 white. We give this variety, pi. VI, fig. 19. 



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