238 MARINE SHELLS 



genus Pyrula, but upon inspection it will be observed 

 to have a fold on the columella. I formerly mistook 

 the young shells for those of F. caniculata or gra- 

 num, which they much resemble in form, in the 

 grooved sutures, and in the spiral striae ; but they dif- 

 fer from them in having a much less elevated spire, 

 by being entirely destitute of armature, either of 

 spines or tubercles upon the angulated ridge of the 

 volutions, and by being marked with coloured lines. 

 In this last character they approach jF. perversus, 

 but they will not be mistaken for that species. 



As the shell advances in growth, the acute edge 

 of the depressed top of the whirls becomes obtuse, 

 and in the adult shell it is nearly obsolete ; in which 

 state the almost regular curve of the whirl is very 

 like that of Pyrula. 



Seba's figures above quoted, are probably intended 

 for this species ; they certainly represent it very well 

 as it appears in the young state. 



I think it highly probable that this is the Bulla 

 Ficns, Var. b. Gmel. which Dillwyn describes un- 

 der the name of Bulla pyrum, with the country of 

 which he was unacquainted. 



PYRULA, Lam. 



Species. 



P. *papyratia. Shell inflated, thin, white, with 

 small pale rufous spots, within pale, dull purplish- 



