CONTRIBUTIONS 



ifuSbf sculptured by some parasitic animal, so as to 

 resemble, iirsamfe degree, the net work of a Flustra. It is 

 entirely covered with this carved work, and at the first 

 view I thought this made it specifically different. A fur 

 ther examination, however, proved the depredator to have 

 no particular preference to species or genera, his workman 

 ship being on many other shells. 



I am not aware that this genus has been observed in 

 the strata of Great Britain. In the admirable tables of 

 M. Deshayes, appended to the third volume of Lyell s 

 Principles of Geology, we have six species, five of which 

 are found in the Paris basin, the Eocene of Mr Lyell. 



The genus has not, to my knowledge, before been ob 

 served in any of the formations of our country. 



FAMILY M ALBANIA. 



GENUS DENTALIUM. Ldnnaus. 



D. alternatum. Plate 1. Fig. 2. 



Description. Shell very slightly curved, with about six 

 teen longitudinal ribs alternating with as many smaller 

 ones ; near the base furnished with irregular lines of 

 growth ; aperture round. 



Length about 1 and 3-4ths inches. 



