280 



PALEONTOLOGY. 



covered, having been regarded as trilobites by some, and 

 referred to the class of insects by others. For an admirable 



FIG. 191. Coccosteus cuspidatus : Agass. 



description of the Cephalaspida, graphic beyond all praise, the 

 student should consult Hugh Miller's " Ol'd Bed Sandstone." 

 The five genera it contains are limited to the Devonian 



