40 G E N U S B L r ('. r I N U M . 



they are raised and noduled. From these distinctions, some 

 authors have sougli**-fco-dWJde-it into several species ; but when 

 we have before us a large number of specimens of different ages, 

 it is impossible not to recognise the identity which exists among 

 them. 



A series of forms, and the differences of the two extremes of 

 age may have led to the error which we are noticing, and to 

 classing the varieties of a single species as several species ; but 

 an examination and study of the intermediate ages, by bringing 

 to view their different relations, lead at once to the necessity of 

 uniting them ; so important is it to examine shells in all the 

 modifications which age and locality can produce in their very 

 forms, before settling their classification. Simple varieties of 

 the shell we are describing, have caused it to be divided into 

 four species ; we will now endeavor to point out the differences 

 which separate them, or the resemblances which unite them, by 

 comparing them successively to our type which we give in plate 

 12, fig. 41. By this examination we shall be convinced that 

 the folds which have been considered as distinctive characters 

 diminish or increase, by insensible degrees, in each of the 

 varieties. 



The first, which we admit in our work as variety B, pi. 12, 

 ^ fig. 41 , b. is described by Gmelin under the name of BUCCINUM 

 affine ; it is the same as that called by Quoy and Gaimard BUC- 

 CINUM cinctum, Voyage de ? Astrolabe, pi. 30, fig. 5-6-7. It is 

 ovate, smaller than our type, of the same color as the B. undo- 

 sum. It is merely ornamented with transverse and rounded 

 threads, and it is only upon some specimens that we begin to 

 perceive slight longitudinal folds upon the whirls. The lip is 

 thin, the crenulations within hardly apparent ; but when the lip 

 curves to form the margin, they become much more visible, and 

 the denticulations of the edge begin also to be recognised. 



This shell inhabits the Straits of Malacca (Martini), the 

 South Sea (Solander), the coasts of Madagascar (Humphreys), 

 the Isle of Vanikoro, of Tonga-Tabou, and many other localities 

 in the Pacific Ocean. 



The variety C, pi. 12, fig. 41, differs from the former by its 

 more globular form, and by the disposition of its threads, which 



