Fig. 1. 
IAAP We 
PLAT HEH XE1t. 
TRACHOSTEUS CLARKI, Newb. (p. 167). 
Post-dorsolateral plate?, half natural size. 
. Eye-orbit with ring of sclerotic plates, inner surface, natural size. 
Mandibles, right and left broken at anterior extremity, natural size. 
. Premaxillary?, natural size. 
. Maxillary ?, natural size. 
Tuberculation where least crowded, showing stellation of bases of tubercles. 
. Tubereles where most crowded, enlarged. 
Cleveland shale, Berea, Ohio. 
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