68 PICTURESQUE SKETCHES 



teeth, readily accounting for the difficulty there is in 

 discovering remains of it in imperfect specimens. The 

 eyes and the apertures of the nostrils were probably 

 extremely small, and placed on the edge of the broad 

 plate, the only indication of the head hitherto met 

 with. The tail was not long, but seems to have been 

 thick and conical, and covered with scales, overlapping 

 each other like the tiles on the roof of a house. 



The departure from the general form of most fishes 

 in this animal is so remarkable, that when first dis- 

 covered, it was looked upon by some naturalists as 

 an insect, by others as a crustacean, and by others 

 again it was thought to be connected with reptiles, 

 owing to the singular resemblance of one small species 

 to the shell of a tortoise. Strange as it undoubtedly 

 is, however, in all respects, this genus forms one of an 

 extinct natural family of fishes, and it is allied to the 

 other genera of its class by the genus Coccosteus, 

 which at one time was thought still more anomalous. 



Fig. 24 



COCCOSTEUS. 



The Coccosteus (fig. 24) is entirely without the wing- 

 like projections which characterise the Pterichthys, and 

 while when seen as in ordinary specimens, lying on 

 its back and crushed, it appears to bear no resemblance 

 to any fish or other animal either recent or extinct, 

 it was not in reality much unlike many well-known 



