255 



PURPURA. 



BUCCINUM PATULUM. LimUBUS. 



Mart. 3, t. 69,/ 758, 759- 

 This genus is the lastin Lamarck's arrangement which 

 presents the appearance of a canal at the base of the 

 aperture: it consequently leads in order of prox- 

 imity to the G. Monodon, Concholepas, Harpa, Doli- 

 um, Buccinum, &c. ; in all of which the canal has quite 

 disappeared, and a notch only remains. The gradual di- 

 minution of the canal, till it became altogether effaced, 

 probably occasioned Linnseus to arrange some of these 

 species with the Murices, and others with the Buccina : 

 there are, however, characters which distinctly mark 

 this genus, and render it necessary to separate the 

 shells composing it from the arrangement of previous 

 authors. The aperture is never narrowed in the mid- 

 dle, either by plaits on the columella, or by teeth 

 on the right side, but is always dilated; the columella 

 smooth, flattened, and terminating in a point at the base, 

 where the notch is more or less obliquely placed, and 

 appears a little ascendant backwards. Shell oval, ei- 

 ther smooth or tuberculated, or angular on the exterior 

 surface ; aperture ovate, dilated, sometimes internally 



