220 UPPER, OR FLINTY CHALK. 



of the exterior crust, or in any degree injuring the inner surface of the 

 shell, which remains untouched ; and notwithstanding these attacks, still 

 equally adapted to every purpose required by the economy of its in- 

 habitant*." 



Siliceous specimens of this fossil are not frequent in Sussex ; but there 

 are scarcely any of the larger Inocerami that do not exhibit traces of the 

 depredation of this parasite, the cells being either empty, or filled with 

 chalk. 



The example figured in Tab. xxvii. was found on the beach, at 

 Brighton ; the shell is entirely removed. 



93. Balanus. Tab. xxxiii. fig. 11. 



The specimen figured, is the only vestige of a multivalve shell that 

 has been noticed in the chalk of Sussex. 



It is gently curved, has two sharp ridges, and not inaptly resembles 

 the beak of a bird ; it is the valve of an operculum of some unknown 

 species of Balanus. 



LocaUty. Upper chalk, near Lewes. 



Crustacea. 



The fossil remains of those species of cancer, in which the crustaceous 

 covering is hard and compact, are not unfrequent in the London clay at 

 Highgate, Sheppey, &c. ; and a few have already been noticed as occurring 

 in the Blue chalk marl of Sussex : but the lobster, cray-fish, and other 

 species, whose structure is more delicate and fragile, are but seldom found 

 in a mineralized state, and rank among the most rare and interesting 

 objects in the cabinet of the oryctologist. 



About seven years since, the remains of an unknown crustaceous 

 animal were discovered in the Upper chalk near Lewes ; but the mutilated 

 and brittle state of the specimens defied all my attempts to ascertain their 

 original form. In the hope, however, that from detached portions of the 

 animal, the required information might ultimately be obtained, every 



* Oyster shells perforated in the manner here described, are frequently found on the sea- 

 shore at Hastings. 



