158 CONTRIBUTIONS 



tioned by M. Deshayes in the Tertiary of Europe twenty- 

 four of these in the Paris basin. Two species only, I be 

 lieve, have been heretofore observed in this country. 

 From the Tertiary of Maryland, Mr Conrad has described 

 the acuticosta. From the Upper Tertiary (Conrad) of Vir 

 ginia, the Miocene of Lyell, Mr C. has described the urn- 

 brifer. It would therefore appear that three species only 

 of Murex in a fossil state are now known here, while 

 eighty-nine are known to exist in the Tertiary of Europe. 



FAMILY ALATA. 



GENUS ROSTELLARIA. Lamarck, 



R. Lamarckil* Plate 5. Fig. 164. 



Description. Shell fusiform, covered with longitudinal 

 ilexed ribs cut by numerous transverse striae, which in the 

 adult are hidden, the whole surface being coated by a de 

 posit ; substance of the shell thick ; spire elevated, acute 

 at the apex ; suture impressed, when coated as in the 

 adult scarcely perceptible ; whorls about twelve, convex 

 in the young, scarcely perceptible through the coating of 

 the adult ; canal at the base short, above nearly erect, 

 extending half way up the spire, where passing in a curve 



x In naming this species in honour of the first conchologist of the age, 

 I do homage to that acumen of science which now penetrates to the 

 study of the naturalist in every quarter of the glohe. 



