56 AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



A portion of one hind leg, including the distal part of the femur with the 

 tibia and fibula, lies over the carapace externally, while the three principal 

 elements of the other leg lie on the inferior side of the carapace. Both legs 

 are extended in the same direction, i.e., forwards. 



"The shaft of the femur has a triangular section, the external face con- 

 cave owing to the prominence of the anterior crest. The external condyle 

 is produced further posteriorly than the internal, and is a continuation of 

 the general disral surface and is not reflected on the posterior face as in so 

 many of the Pelycosauria. The anterior face is flat above and shallowly 

 concave at the condylar border below. The head of the tibia is expanded 

 and the shaft narrowed, as in the Pelycosauria. It is straight, while the 

 fibula presents towards it a concave outline; and the two extremities of the 

 latter are about equally expanded. 



"The surfaces of the vertebral centra are slightly concave anteropos- 

 teriorly. The intercentra are somewhat swollen and knoblike on the inferior 

 face. It is probable that the ribs are less closely adherent to the carapacial 

 bars posteriorly than anteriorly. As already remarked, anteriorly the ribs 

 emerge between the bars to form part of the surface; medially the ribs are 

 below the bars, but touch them. Further posteriorly a cross-section displays 

 a rib which does not touch a bar, except perhaps at the extremity, as the 

 curvature would indicate: but this part is broken off. The superior surfaces 

 of the carapacial elements are of dense bone marked with coarse and fine 

 fossse and intervening elevations irregularly distributed. 



"The size of this animal is about that of the adult of the larger Japanese 

 salamander, Megalobatrachus. 



"Measurements. 



MM MM 



"Width of skull between meatus audi- Length of femur 67 



torius 75 Anteroposterior diameter of femur: 



Width of skull between orbits 31 Proximally 23 



Width ofskull between orbit and meatus 15 Distally 20 



Width of orbit transversely 27 Length of tibia Ji 



Length of skull above posterior to orbits 65 Long diameter of head of do 17 



Depth of malar bone at middle of orbit. 12 Long diameter of distal end of do 13 



Depth of mandible bone at middle of Length across the ends of six ribs 75 



orbit 14 Length of part of carapace preserved.. . 105 



Length of tooth external to alveolus ... 3 Width of a posterior carapacial bar. ... 10 



Length of clavicle (chord) 78 Width of an anterior carapacial bar 8 



Widths of clavicle: Diameters of a vertebra: 



Proximal 22 Anteroposterior 8 



Median 4 Transverse 16 



Distal 21 Diameters of an intercentrum: 



Transverse diameters of humerus: Anteroposterior 6 



Head 3S Transverse 12 " 



Shaft S 



The species mimeticus was described in the same paper: 

 "This species is represented by a skull with lower jaw in place which 

 is connected by a band of matrix to a carapace, and some of the bones of 

 one of the limbs. Greater and smaller parts of thirteen bands of the cara- 

 pace are preserved. 



"The skull is short and wide. The superior surface is nearly flat from 

 the posterior border to between the nostrils. The muzzle does not project 

 beyond the mouth border. The orbits and nostrils are not superior in direc- 

 tion, . although the superior orbital border is excavated. The nostrils are 



