1869.] CANADIAN ZOOLOGY. 425 



Many of the fossil Brachiopods differ considerably from those 

 that are recent, and are placed iu different families. We can 

 recognise their general resemblance to the modern forms by the 

 impressions of the mantle and muscles on the valves. Fig. 95 

 represents the interior of the dorsal and ventral valves of an 

 Orthis, showing the muscular and mantle impressions, teeth and 

 foramen. 



Oethis sthiatula, after Woodward. 



(A) Dorsal valve, showing the muscular impressions at (d); also the vascular 

 impressions of the mantle, and the notch, tooth and brachial processes in the 

 hinge. 



(B) Ventral valve, showing the impressions of the hinge and pedicel muscles. 



YOL. IV. 



K. 4 



