THE MICROSAURIAN FAMILY SAUROPLEURID.E. 167 



alveoli which resemble in a great degree the alveoli of the jaw of some small animal. 

 The ventral scutellation is broad anteriorly, but becomes more slender posteriorly 

 and shortly posterior to the cloacal region disappears. 



The fore limb is represented by the upper portions of the ulna and radius and 

 2 digits of the right hand. The digits are long and slender and seem to represent 

 digits I and II, since they show evidences of 3 and 4 phalanges respectively. The 

 portions of the fore arm preserved are too meager for description. 



The vertebrae have already been characterized as of the type first described in 

 Urocordylus. The neural fans are not much, if any, wider than the haemal fans. 

 They are both situated on an elongate spine with a slender base. The edges of the 

 two fans are pectinated and the dorsal spine is distinguished by the presence of a 

 longitudinal groove in the center of the spine. The length of the tail may have 

 been considerable, judging from the character of the vertebrae preserved 



MEASUREMENTS. 



ram. mm. 



Length of specimen 150 Width of the same vertebra with spines 20 



Width of belly, maximum 28 Height of neural spine 8 



Length of lateral chevron plate 7 Height of haemal spine 8 



Width of lateral chevron plate 1.75 Width at distal end of haemal spine 3 



Length from tip of lateral chevron to median Width at distal end of neural spine 3.5 



angle 10 Length of foot, as preserved 12 



Length of a caudal vertebra 10 



Genus LEPTOPHRACTUS Cope, 1873. 



COPE, Proc. Phila. Acad. Nat. Sci., p. 340, 1873. 

 COPE, Geol. Surv. Ohio, n, pt. 11, p. 399, 1875. 

 COPE, Proc. Am. Phil. Soc., xx, p. 461, 1882. 



Type : Leptophractus obsoletus Cope. 



The genus was established on various parts of the cranium of a large amphibian. 

 The only parts which can with certainty be referred to the genus are the upper and 

 lower jaws of 3 specimens. These bear large teeth, round in section at the base, 

 but with acute compressed apex, with a cutting -edge on the anterior face; the 

 enamel is delicately grooved, as an external indication of the labyrinthic structure. 

 A characteristic feature is seen in the presence of a large elongate tooth in the upper 

 jaw, in the position of a canine which much exceeds in length any of the others. 

 The sculpture of the cranium is but little marked in the known specimens. In the 

 type the lower jaw is marked with inosculating grooves. Three species are known, 

 which are among the largest of the Linton Amphibia. 



Leptophractus obsoletus Cope. 



COPE, Proc. Phila. Acad. Nat. Sci., p. 340, 1873. 

 COPE, Geol. Sun.-. Ohio, n, pt. II, p. 399, 1875. 

 COPE, Proc. Am. Phil. Soc., xx, p. 461, 1882. 



Type: Specimen Nos. 55 G and 57 G, American Museum of Natural History. 



Horizon and locality : Linton, Ohio, Coal Measures. 



The species was about as large as an adult Florida alligator, and probably 

 exceeded or at least equaled in size any of the Carboniferous Amphibia. The fol- 

 lowing account is taken directly from Professor Cope's " Batraehia of the Ohio Coal 

 Measures" (123). The description has been verified from an examination of the 

 type material. 



