62 



THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



They are quite diflferent from 





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The ventral armature is represented by a patch of chevron rods 21 mm. in 

 length. The rods take a very peculiar form, being short cresccntic bundles of 

 fine rods, hair-like in appearance. In one of these bundles I count 5 smaller rods. 

 The bundles are arranged in rows similar to the pattern so characteristic of the Car- 

 boniferous Amphibia, as described elsewhere. The patch of ventral armature pre- 

 served belongs to the abdominal region. A single row of the crescentic bundles 

 measures 11 mm. 



Both scapulae are preserved in their entire form 

 those of any other genus, being broadly 

 crescentic with a posterior concavity and 

 an anterior protuberance. The anterior 

 surface of both scapulae is obscured. Vas- 

 cular foramina occur near the base of both 

 scapulae; there being three of them in the 

 right scapula, arranged in the form of an 

 isosceles triangle. The morphology of these 

 foramina is uncertain. They have never 

 been observed among the Carboniferous 

 Amphibia, and, so far as I am aware, 

 they are entirely unknown among higher 

 vertebrates. 



The temnospondylous Amphibia of the 

 Carboniferous and Permian possess, in the 

 co-ossified scapula-coracoid, three fora- 

 mina, very similar to the ones in the pres- 

 ent form, but they are confined to the 

 coracoidal region and, in the Branchio- 

 sauria, as identified by Credner, the cora- 

 coid is a free element, although I have 

 never been sure of its identity among 

 American forms. Williston has called these 

 foramina the glenoid, the supraglenoid, and 

 the supracoracoid foramina (Journal Geol- 

 ogy, XVII, No. 7). They are not, however, 

 to be correlated with the three foramina 

 above mentioned, since in the Temnospon- 

 dylia the foramina belong with the coracoid and not with the scapula. The 

 condition of the Temnospondylia occurs in the bony fish Xiphactinus audax 

 Leidy, and an analogous condition obtains in the reptiles, as in the Mosasaurs 

 and Dinosaurs. 



Near the outer edge of the right scapula there is a large fragment preserved, 

 which, I think, must be the misplaced clavicle. It is obscurely triangular or, more 

 exactly, spatulate. The interclavicle is represented by fragments only, and seems to 

 have had a narrow form. 





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Fig. 14a 



Skeleton of Mazonerpeton longicaudatum 

 Moodie. c, carpus; d, clavicle; cr, caudal ribs; cv, 

 caudal vertebrae; h, humerus; /, femur; or, orbit; 

 r, radius; sp, sclerotic plates; sc, scapula; u, ulna; 

 vs, ventral scutelte. From Mazon Creek. Original 

 in Yale University Museum. 



