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 um- 

 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 

 flexed ribs cut by numerous transverse strife, 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 



* 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 globe. 



