107 



BELLEROPHON Montfort. 



Gen. Char. An involute, univalved shell ; 

 nearly spherical ; the last whorl enclosing 

 the others ; aperture arched, terminated by 

 the extremities of the transverse columella, 

 (or axis), and furnished with a sinus in the 

 centre of its outer edge. 



•i-N general form the shells of this genus resemble the 

 Nautili, bat they have no septa; the two sides, if they 

 may be so called that are indicated by the extremities of 

 the axis, are nearly similar, in which particular they are 

 flistinguished from Ovula, Bulla, and most other invo- 

 lute Genera ; they are sometimes umbilicated ; the front 

 edge of the aperture has a sinus in it, from which, in 

 most species a band runs round the whorl, and forms a 

 kind of keel ; as this keel is very variable in size, the 

 presence of it is not considered as essential to the 

 Genus, but will serve to divide it into two sections by ; 

 the^rs^ without ; the second^ with a central band. 



Had not M. Defrance ascertained from a specimen 

 formerly belonging to De Montfort, that his Bellero- 

 phon was not a chambered shell,* the Genus would 

 probably have long remained without being recognized, 

 although several species are far from being of rare oc- 

 currence in the older Limestone rocks ; it is not unlikely 

 that De Montfort was misled in his generic character, 

 by imperfect specimens of Nautilus biaijgulatus,f t. 458. 

 f. 2, which hfe might consider as portions of the same 

 species, as it occurs in the same limestone. 



JEllipsolites ovatus, t. 37, belongs to this Genus, 



• Annates des Sciences Ni^turelles Vol. I. p, 264. 

 Zoological Journal, No. 2. p. 223. 



1 1 have just received specimens of tliis from Ireland, several inches in 

 diameter, and also learnt that it was a mistake to give Bristol as the 

 locality of the specimen figured^ it also came from Ireland. 



