97 



of H. Bullaoides having been figured, under a convi6lion 

 that a fpecies fo called in the Portlandian cabinet was per- 

 fe6lly diftinfl from the Linnaan Bulla, 



For a figure of Bulla hypnorum we refer to the Tranfac- 

 iionsof the Linnaan Society, vol. viii, tab^ 4. fig3 ; and to 

 PuLTENEYjin Hutchins's Dorfet, tab. 18. fig. 20. 



Bulla rivalis, Lin. Trans, viii. p 126, t. 4, f. 2. Rivalis, 



Shell ovate, pellucid, with five reverie prominent fpires, 

 with an acute apex : aperture ovate-oblong. 



This fpecies of heteroftrophon Bulla is in its contour a 

 medium between Bullafontinalis and hypnorum ; nevertheless 

 it is evidently diftindl: from either. It is readily difiinguiflied 

 from the former by being much more produced, more acute 

 in the apex, and more contra6led in the low er part of the 

 aperture; and /rom the latter by being. more conic in the 

 fpires, and more acutely pointed. Since, however, doubts have 

 been exprelTed by feme authors of the dillinition between 

 the two laft mentioned fpecies, fimilar doubts may be enter- 

 tained with refpeft to this, and may rather ferve to confirm 

 the opinion of thofe who have not the means of a6lual com- - 

 parifon, by fuppofing it an intermediate growth connecting 

 ihem. It is but jufticc however to fcience to remark, that 

 as fjr as our humble opinion can ftrengthen the refpeftable 

 anthority of thofe who firfi: introduced this fliell to public 

 notice, we have no hefitation in b^'ariiig record of the iden- 



N tity 



