G E N U S B U C C 1 N U AI . 99 



surrounds the suture, and the other only borders the circum- 

 ference. Epidermis thick and brown. 



Length 6 lines. Width 4J- lines. 



Inhabits the Mediterranean, upon the coasts of France, of 

 Corsica, and of Sicily ; the Adriatic, and the Ocean, towards 

 the gulf of Gascony. 



Risso, in his work on the South of Europe, has described two 

 specimens of this species under the names of CYCLOPE Dono- 

 viana and CYCLOPE pellucidus, p. 271, No. 718 and 719. These 

 appear to be only worn and discolored specimens. 



The principle too often followed for the establishment of 

 groups among shells, has given rise to many errors; these 

 groups, arranged by an examination of the superficial charac- 

 ters of shells, comprise a great number of dissimilar species, be- 

 longing even to other genera ; and species are rejected as dis- 

 tinct, which ought to be united. These characters, such as the 

 color, the folds, the striae, the whirls, run into each other in a 

 manner so insensible, or differ so completely, that it is impossi- 

 ble by them to point out 'the limits between species. 



Thus, in the genus BUCCINUM, which we have just been de- 

 scribing, we see numerous specimens, obviously varying in the 

 longitudinal folds, tubercles, and transverse stria?, which are 

 found upon their surface ; in some, these folds, at first very prom- 

 inent, disappear, and sometimes leave tubercles which shew the 

 vestige of them ; in others the striae are less distinguished. 

 Sometimes the whirls are strongly canaliculated, whilst upon 

 other shells of the same species, the suture is scarcely apparent. 



These variations depend upon differences of sex, of age, or of 

 locality. But the same species invariably presents two charac- 

 ters which are constant, or at least subject to less variation, that 

 of the general form, and the aperture of the shell, which, I think, 



