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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 56. 



left half of this girdle articulated with the almost perfect hmb and 

 foot. (See pi. 72, fig. 2.) 



I have carefully compared these bones with the homologous 

 elements of the smaller and better known species, Dimetrodon 

 incisivus, but, except for their larger size, fail to detect differences 

 which might be of help in distinguishing them specifically. 



Fig. 5.— Left scapula of Dimetrodon gic.as Cope, No. 8635, L'.S.N.M. About one-third natubal 

 SIZE. Lateral view. cf. coracoid foramen, cor., coracoid; mcor., metacoracoid. 



Scajmla. — The unusually well-preserved left scapula coossified 

 with the coracoid and metacoracoid is known in figure 5. 



The suture defining the junction of scapula and coracoid has been 

 entirely obhterated, but between the coracoid and metacoracoid it 

 remains distinct as shown in figure 5. 



From end to end there is a decided convex curvature which con- 

 forms well to the form of the body and also throws the expanded 



