THE MICROSAURIAN FAMILY MOLGOPHID^E. 149 



MEASUREMENTS OF TYPE SPECIMEN OF MOLGOPHIS BREVICOSTATUS COPE. 



mm. mm, 



Length of 7 vertebrae 105 Length of a rib on a curve 24 



Length of i centrum 16 Greatest thickness of same 2.5 



Diameter of same vertically 1 1 



Molgophis wheatleyi Cope. 



COPE, Geol. Surv. Ohio, n, pt. 11, pp. 369, 370, pi. xlv, fig. i, 1875. 

 COPE, Trans Am. Phil. Soc., xv, p. 263, 1874. 



Type: Specimen No. 1101 G, American Museum of Natural History. 



Horizon and locality: Linton, Ohio, Coal Measures. 



A critical study of the type specimen of this species does not reveal anything 

 essentially different from the description of Cope. The following is taken from his 

 report (123): 



"Established on a specimen which exhibits about twenty-five vertebrae with ribs, and 

 the posterior portion of the cranium. No traces of abdominal scales or rods, thoracic 

 shields, or limbs are visible. By such negative characters it is referable to the genus Mol- 

 gophis, although the definition of this genus is incomplete. The present batrachian may, 

 indeed, be ultimately found to be an Ophiderpeton, to which it also bears some resemblance. 



"The specimen is that of an animal of very much smaller size than the M. macrurus. 

 The vertebrae are of moderate length, with a low neural spine, and centrum angular at 

 the sides and truncate at the articular extremities when in place. The ribs are rather 

 short, slightly curved, apparently hollow and intercentral in position. Although the ver- 

 tebral centra are ossified, the elements of the cranium have a larval appearance. These 

 consist of two parallel bony plates, which resemble the fronto-parietal bones of the frog; 

 they are slightly separated from each other, but do not inclose a fontanelle. A wedge- 

 shaped bone extends from the outside of the front of each of these, acuminate behind, 

 and widening anteriorly in the position of a postfrontal bone. In front of the posterior 

 border of each parietal, on its outer side, a bony enlargement arises which contracts out- 

 ward and forward into a narrow element which curves forward beneath the postfrontal. 

 These look like an anteriorly directed quadrate with articular bone, such as seen in the 

 larvae and some adults of existing batrachians. These determinations will require con- 

 firmation from additional material. In the meantime it is evident that the present specimen 

 can not be referred to any of the other species herein described. The elements of the 

 cranium are entirely smooth with no sign of sculpture, and in this respect the present 

 species is unlike any of the other known from the Carboniferous." 



The vertebrae are not so clearly marked as one is led to believe from Cope's 

 figure. 



MEASUREMENTS OF THE TYPE OF MOLGOPHIS WHEATLEYI COPE. 



mm. mm. 



Length of entire specimen 63 Width of a vertebra 1.5 



Length of portion of skull preserved 9 Length of a posterior rib 5 



Posterior width of same 8.5 Width of rib 5 



Length of a vertebra 1.5 



The species is dedicated to Charles M. Wheatley, of Phcenixville, Pennsylvania, 

 one of the original investigators of the Linton deposits. It is a part of the New- 

 berry Collection. 



Additional material of this species is represented by specimens Nos. 7 and 8699 G 

 of the American Museum of Natural History. They are both very unsatisfactory. 

 They consist of molds of the vertebral column, with in one case an enlargement at 

 one end which may represent the head, and if such, the specimen probably repre- 

 sents a distinct species. The impression, No. 7, contains molds of about 30 ver- 



