MORPHOLOGICAL REVISION 91 



have a very similar appearance to those of the maxillary; the base of the crown is 

 swollen and the inner edge is continued upward in a cone which was sharp originally, 

 but it seems to be worn blunt by use. The articular region shows two cotyli for the 

 condyles of the quadrate and is expanded laterally for their accommodation, as in 

 the Diadechdcc. Though the posterior portion of the jaw is very high, there is no 

 distinct coronoid process, and there are no vacuities in the outer surface of the jaw. 

 The relations of the various bones can not all be made out, but it is evident that the 

 splenial extends far forward and took part in the symphysis." 



Measurements. 



mm mm 



Length of the lower jaw of No. 4685, perfect 31 i Length of a caudal 17 



Width across the posterior end of the skull . 28 ! Width of distal end of a humerus . ... 12 



Length of three middorsals 23 j Probable length of same, about .... 40 



No specimens have been found with limb bones and vertebrae definitely in 

 association with the skull. In one locality a considerable number of vertebrae and 

 limb bones of the proper size were found with three skulls, but as this was in a bone 

 bed and as there were bones of other animals mingled with them there can be no 

 certainty that the skulls and limb bones belong together. Three vertebrae are shown 

 in fig. 35, a and b; the vertebrae are all notochordal and vary considerably in form, 

 from short and high dorsals to very elongate 

 caudals. The dorsal vertebrae are short and 

 wide, with wide zygapophyses and low neural 

 spines ; the transverse processes stand out at 

 right angles from the sides of the centrum and a b 



the neural arch just below the anterior zygapo- Fig. 35.— Dorsal vertebra of Boiosmrus (?). xf. 



_. . J . r „ - . -i 1 No. 4686 Am. Mus. a, top view; b, lateral view. 



physes. I he head of a small femur is without 



well-defined articular surface. The distal end, in a second specimen, shows that 

 the femur was long and slender without well-defined entepicondylar or ectepicondy- 

 lar processes. There is the usual entepicondylar foramen. 



A fragment of a pelvis, No. 4326 Am. Mus., shows that the ischium and pubis 

 had the primitive broad and plate-like form. There seems to have been two sacrals. 



The type specimen is in such poor condition that little detail can be made, but 

 the teeth of the lower jaw show the characteristic form and permit the identification 

 of other specimens. 



Pariotichus brachyops Cope. 



Characteristic specimen: A small skull, No. 4760, Am. Mus. Nat. Hist. The 

 type specimen is in extremely poor condition and nothing can be made out concerning 

 the arrangement of the bones of the skull or the condition of the surface. The 

 maxillary teeth are fairly well preserved and from these the homotype has been 

 identified. The type skull is similar in appearance to the small amphibian Lysoro- 

 phus, but the teeth are totally unlike any amphibian from the Permian. On the 

 lower surface is a single broad plate, the component elements of which can not be 

 made out. It resembles the great parasphenoid of Lysorophus, but equally so the 

 plate formed by the parasphenoid and basisphenoid in Gymnarthrus. 



The homotype is in good preservation. This shows that the skull was low and 

 the anterior end of the muzzle blunt. The orbits are large and circular and look 

 laterally and a little upward. There is the same arrangement of the bones of the 

 temporal region as in the Captorhinidce; that is, there are but two bones over the 

 temporal region. The supraoccipital plates are vertical at the back of the skull. 

 7 



