234 CLASS III. GASTEROPODA. ORDER VII. PECTINIBRANCHIATA. 
the many genera into which they have been distributed by succeeding 
writers. Bruguiére and Lamarck have been the chief promulgators of 
the subsequent alterations, and there are three genera, Cyllene, Pollia, and 
Bullia, introduced by Gray, which yet remain to be appreciated. The last 
of these, Bullia, is certainly the best entitled to notice ; it distinguishes a 
somewhat numerous and characteristic series partaking of the characters 
of the Terebre. 
The shell of Buccinum may be described as being ovate, or oblong, 
and occasionally somewhat turrited, with the base either emarginated, or 
slightly canaliculated ; the spire is elevated, and rather sharp at the apex ; 
the aperture is orbicular, and angulated at the upper part, and the colu- 
mella, which is thick, and mostly smooth, is widely expanded, and ends in 
a point ; the outer lip is a little reflected, sometimes crenated, and often 
armed towards the lower part with a slight, dentiform process ; the inte- 
rior of the shell is in some instances lightly sulcated, and the operculum 
is horny. 
Examples. 
Pl. CCLXVIII. Fig. 1. 
Buccinum pyrostoma, Nobis, Proceedings Zool. Soc., 1842. 
Phos pyrostoma ? 
Pl. CCLXVIII. Fig. 2. 
Buccinum unposum, Linneus, Syst. Nat., p. 1203. Lister, Historia 
Conchyliorum, pl. 938. f.33. Kiener, Iconographie des Coquilles 
vivantes, pl. 12. f. 41. a, b,c. 
Nassa undosa, Martini. 
Buccinum affine, Gmelin. 
Triton undosum, Lamarck. 
Pl. CCLXVIII. Fig. 3. 
BuccinuM ELEGANS*, Nobis, Proceedings Zool. Soc., 1842. 
Pl. CCLXVIII. Fig. 4. 
BuccitNuM MONILIFERUM, Valenciennes. Kiener, Iconographie des Co- 
quilles vivantes, pl. 3. f. 8. 
* From the collection of R. B. Hinds, Esq., R.N. 
