THE AMERICAN COAL MEASURES BRANCHIOSAURIOE. 63 



The humeri recall those of Micrerpeton. They are somewhat elongate and appar- 

 ently cylindrical in their normal condition, although somewhat flattened in the fos- 

 sil. The shaft is considerably constricted at the middle and the ends are expanded, 

 in which expansion the lower end exceeds. The ends are abruptly truncate, indi- 

 cating a small amount of endochondral ossification or its entire absence. 



The mesopodial elements, unlike what is described for Cephalerpeton, are quite 

 dissimilar in form, recalling the condition in Mesosaurus brasiliensis McGregor. The 

 larger element is, apparently, the ulna. It has the lower end greatly expanded and 

 the shaft is curved outward, resembling very much a reptilian ulna. The radius 

 is much smaller than the ulna, lacks the lower expansion, and is shorter by i mm. 



The carpus is represented merely by a blank space, with evidences of impres- 

 sions of cartilage in the sandstone. The hand of the right side contains 4 phalanges. 

 There are 2 phalanges preserved in the first digit, including a sharp-pointed ter- 

 minal phalanx, and the second digit has only the metacarpal. The third has the 

 metacarpal and the first phalanx, which does not differ in form, but only in size, 

 from the metacarpal. The fourth digit contains only the metacarpal. Of the 

 left hand there are portions of 3 digits preserved, including 3 metacarpals and a 

 phalanx, which in structure are not different from those of the right hand. 



The ilium of the left side is preserved, apparently entire. It is elongate and cylin- 

 drical, its upper end adjoining the twenty-eighth vertebra. The head of the femur 

 lies close to the lower end of the ilium, so that that element must have been suspended 

 in the flesh, much as in modern salamanders. It could not have been of much use as 

 a support for the body. The form of the femur is not unlike that described for the 

 humerus, save that its lower end is smaller than the upper, while in the humerus 

 the extremities are of equal diameter. A portion of the right femur is preserved, 

 extending in an opposite direction to the left. 



MEASUREMENTS OF THE TYPE. 



mm. mm 



Length of entire specimen 64 Length of clavicle 4.5 



Length of portion of skull preserved 6.5 Width of same 1.5 



Posterior width of same 7 Length of right humerus 6 



Width across orbits 1 1 Distal width of same 2 



Long diameter of orbit 3 Length of ulna 3.25 



Transverse diameter of orbit 1 .75 Distal width of same I 



Interorbital width 4.75 Length of radius 3 



Length of dorsal vertebra; 48 Width of carpal space 2 



Length of caudal scries 1 1 Length of metacarpal 1.74 



Length of anterior dorsal centrum 2 Length of first phalanx 1.75 



Length of anterior dorsal rib 4 Length of distal phalanx of right hand 35 



Length of anterior caudal rib 1.75 Number of chevron rods in l mm 4 



Length of scapula 5 Length of ilium 2.25 



Greatest width of scapula 4.25 Length of femur 4 



Probable length of interclavicle 6 Proximal width of femur 1 .50 



Width of same 3 



Mazonerpeton costatum Moodie. 

 MOODIE, Kans. Univ. Sci. Bull., vi, No. 2, p. 341, pi. 2, fig. 3; pi. 8, fig. 4; pi. 9, fig. 2; pi. 10. 1912. 



The remains on which the present species is based are inclosed in a much frac- 

 tured nodule. The parts of the animal which have been identified are: a part of 

 the skull and left mandible, two clavicles, a humerus, impressions of several verte- 

 brae, a portion of the dorsal region of the body with several ribs, two portions of the 

 caudal region with several ribs and unidentified fragments. (Plate 4, fig. 3.) 



