228 UPPER, OR FLINTY CHALK. 



Messina, described by Spallanzani, (and which appears to agree in its 

 characters, with the fish figured by Scilla, Tav, xxvii.) has also teeth of 

 a similar structure. It may however be questioned, if the present spe- 

 cimen belongs to the same kind of animal ; or whether it may not be the 

 fin-bone of a fish allied to the Balistes. It consists of six sharp points or 

 spines, anchylosed at the base, and attached to a narrow, bony or car- 

 tilaginous process. 



The example figured, is probably the only fossil of the kind hitherto 

 discovered in the chalk formation. Scilla's specimens were found in the 

 Umestone of Malta, which is situated above the chalk; and those of the 

 Enghsh authors above referred to, were collected from different localities 

 of the London clay. 



Locality. Upper chalk, near Lewes. 



106. Tooth of ? Tab. xxxiii. fig. 7. 



The fossil here represented is of a very singular character. It is of a 

 lanceolate shape, of a dark brown colour inchning to black, and its surface 

 is marked with numerous irregular fissures fiUed with chalk; this ap- 

 pearance is constantly observable in every specimen. The edges are 

 acute, and entire. 



I am unacquainted with any teeth, either in a fossil or recent state, 

 that possess a similar structure. 



Locality. Upper chalk, near Lewes. 



The remains we are next to examine, bear considerable analogy to the 

 corresponding parts of certain species of Balistes, or file-fish : to illustrate 

 the subject, we shall therefore insert a brief description of the recent 

 animals. 



BALISTES. 



The fishes of this curious genus, have the head compressed, and close 

 to the body, appearing as if it were a continuation of the trunk. The 

 mouth is narrow, the teeth in each jaw are eight in number, of which the 

 two anterior ones are the longest ; there are also three interior ones on 

 each side, opposite the intervals between the external row. The aperture 



