THE MICROSAURIAN FAMILY TUIHTANID/E. Ill 



centra are unusually long and slender, with the ends rounded. The humerus of the 

 right side is preserved. It is a long, slender bone with expanded extremities. There 

 is no evidence of abdominal armature nor of ribs (fig. 22, E). 



The discovery of this form in the Linton deposits is of considerable interest in 

 that it indicates a wide range in size and character of the fauna of the time. The 

 forms now known from the Linton beds range from Odonterpeton, which possibly had 

 a total length of 2 inches in life, to the form designated Macrerpeton huxleyi Cope, 

 with a skull of at least 8 inches in length and whose body may have attained a length 

 of some feet. The large rib described below undoubtedly indicates a large form of 

 the ancient Amphibia from Linton, as do also the vertebrae described by Marsh in 

 1863 from Nova Scotia. 



MEASUREMENTS OF THE TYPE. 



mm. mm. 



Length of animal, as preserved 18 Length of tooth 0.25 



Length of skull 6.5 Length of vertebra 1.45 



Posterior width of skull 5.5 Width of vertebra 35 



Length of side of skull 6.5 Length of humerus 2.25 



Diameter of orbit 65 Distal width of humerus 35 



Interorbital width . . 2 



