EXTINCT BATRACHIA. 403 



SaUROPLEURA DIGITATA, Cope. 

 Proceed. Acad. Nat. Sci., Philad., 1868, p. 216 ; Transac. Amer. Philos. Soc, XIV., p. 15. 



This species is represented by but one individual, which has been 

 spread over a surface of the coal slate, exhibiting ventral armature, dor- 

 sal region with ribs, and anterior and posterior limbs. Of skull and cau- 

 dal vertebra? nothing remains. 



The dermal bands are arranged as in Oestocephalus, i. e., in parallel 

 lines directed obliquely forwards and continuous on the median line, 

 forming there a chevron. The component scuta are oat-shaped, and 

 acuminate at both ends. They are moderately imbricate in an antero- 

 posterior section. On the pectoral region between the fore limbs the 

 series of scutella assume different directions, forming chevrons directed 

 backwards, and forming with those of the belly a complex X. 



The humerus, ulna, and radius are rather stout, and of a size relative 

 to the body, as in common types of existing sauria; the ulna and radius 

 separate. There is no carpus, but five well-developed digits have pha- 

 langes in the following numbers, commencing on the inside : 3, 4, 5, 6, 5. 

 The last phalanx of the second is obscured, and it is not positive that 

 the number is as given ; it is more probable than that it should have 

 been 3. The outer toe has been more slender than the others ; the distal 

 phalanges of all the toes are short conic, as in Salamanders. Thus this 

 form differs from Amphibamus, where the numbers are 3, 3, 4, 5, 4, show- 

 ing a lower development of limbs. 



The ribs are long and curved as in reptiles, and judging by their dis- 

 tances the vertebrse are short ; the latter are not well defined, but there 

 is no indication of pronunent spines of any kind. 



The pelvic bones and portions of those of the hind limbs are present, 

 but so obscured and confused as not to be made out. Enough remains to 

 show that the hind limbs are considerably longer than the anterior. 



This species had a length of body about equal to that of a fully grown 

 Chamseleo vulgaris of the largest size, or of a half-grown Menopoma. 

 Thirteen ribs on one and several on the other side are jireserved ; where 

 they terminate, probably at the pelvic region, some small or rudimental 

 ribs project from the two or three first caudals. Three ribs and their 

 interspaces extend over five lines. The humerus is broken, but its 

 length can be clearly made out to be seven lines ; it has no condyle, and 

 is dilated at both extremities. The ulna and radius are distinct, trun- 

 cate, hollow, and dilated at the ends. Length of ulna, 5.1 lines; distal 

 width, 1.8 lines. The fourth toe is considerably longer than the others ; 



