.:3t: " f :. : CONTRIBUTIONS 



beautifully sculptured 1 by some parasitic animal, so as to 

 '- fesemWe, in gome 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 MALDANIA. 



GENUS DENTALIUM. Lmnasus. 



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. 



