34 



NEW YORK STATE MUSEUM 



Professor Patten for the restoration of the latter genus shown in text 

 figure 12. 



General organization. Before entering into a description of individual 

 forms, it is first of all necessary to understand the general structure of an 



Fig. 8 



Fig. 7 Restored outline of Pterichthys milleri Agasslz ; dorsal aspect, x % 

 Fig. 8 The same from the ventral aspect, x K (Both figures after Traquair) 



Asterolepid, and to know the names by which the various parts found in the 

 fossil state may be distinguished. For this purpose it is well to take 

 Pterichthys, as being the genus best known in its entirety, if not in every 

 manner of detail. 



The body armor consists of osseous plates closely fitted together, 



