THE GASTROPODA 103 



5. Rimella rimosa (Fig- 30) is found in the Barton 

 beds of the Hampshire coast, and belongs to a family 

 which is nowadays almost confined to tropical seas. In 

 shape it differs from turreted shells in that the anterior 

 part of the last whorl (and of other whorls, though this 

 is not seen externally) is drawn out to a point of such 

 length that the last whorl almost repeats the shape of 



P.C 



A.C. 



FIG. 30. RIMELLA FISSURELLA (LAMARCK), EOCENE. 

 (Natural size.) 



This species is very close to R. rimosa (Solander). A. C. , Anterior canal : 

 P.C., posterior canal ; V t varices. (After Deshayes.) 



the spire in inverted position : such a shell is spindle- 

 shaped or fusiform. The aperture and anterior canal take 

 part in this drawing-out. The outer lip is thickened, and 

 the posterior end of the aperture is drawn out into a long 

 narrow channel (posterior canal) which runs right up the 

 spire in close contact with it. This canal is analogous 

 to the notch of Emarginula and its allies, but does not 

 indicate any near affinity with them. 



