EXTINCT BATRACHIA. 393 



The humerus originates at the outer posterior angle of the lateral 

 thoracic scutum. It is relatively as large as that of a frog, is contracted 

 medially, and much expanded distally. It is followed at a short interval 

 by a shorter ulna, which is also expanded at the ends and contracted at 

 the middle. Then succeed numerous well-developed phalanges, which 

 are so scattered as to render it impossible to ascertain the number that 

 compose the digits, and how many of the latter existed. 



The vertebr8e are osseous and with slightly concave extremities on a 

 lateral view; they are subquadrate in outline; their spines are not dis- 

 tinguishable. There are twenty-two to twenty-three pairs of osseous 

 ribs, which are slender, rather short, and strongly curved backwards. 



Length of specimen as preserved, 0.097 m. ; do. of head, .024 ; width 

 of head posteriorly, .020; depth of ramus mandibuli, .004; eight apices 

 of teeth cover, .005 ; length of twenty-three vertebrae, .062 ; length of me- 

 dian pectoral scuta, 0.010; width do., .C'lo : width of the three scuta, .010; 

 length of process of median scuta, .005 ; length (;F humerus, .009 ; width do., 

 .004; length of ulna, .006; width do., .002; length of phalanx, .003; ex- 

 panse of longest ribs, .015; length of a long rib, .009. 



Besides the generic characters already pointed out, this species differs 

 from the Tuditanus longipes, to which it has some resemblance, in the 

 much shorter fore limbs and shorter vertebral column in the anterior 

 region of the body. 



Tuditanus brevirosthis, Cope. 



Transactions American Pliilosophical Society, April, 1874. 



Represented b}^ two individuals, and probably by part of a third. 

 Those with the cranium show that this part is large in comparison with 

 the size of the body, and is as wide as long, with broadly rounded muz- 

 zle. The orbits are large, and situated for the greater part in front of a 

 line marking the anterior third of the length of the head. The bones 

 of the head are coarsely sculptured with radiating ridges and with some 

 tubercles posteriorly; the supratemporal exhibits radii which extend 

 outwards. The teeth are in two rows on that part of the maxillary arch 

 anterior to the orbits ; they are of equal sizes; the outer row appears to 

 be directed more obliquely outwards than the inner. The former num- 

 ber five in .002 m. The thoracic shields are rather large, and have coarse 

 radiating ridges. 



Vertebral centra and arches are not well distinguished in two individ- 

 uals, but, instead, an axial mass, which may represent chorda dorsalis. 

 In one, three diapophyses are distinctly developed at the sacral region. 



