SYSTEMATIC REVISION 39 



In 1896 (41) there was given an extended account of the genus Pariotichus, but 

 as this was based on Captorhmus (P.) aguti it may be taken as an account of Cope's 

 observations on that genus: 



"The maxillary teeth display the enlarged median tooth characteristic of the 

 species referred to Ectocynodon, although it is less prominent than in some of the 

 latter, and it is probable that the premaxillaries display corresponding enlargement. 

 The type of Ectocynodon (E. ordinatus Cope) is in the same condition as regards 

 teeth of the premaxillary series, but a long tooth is present near the mandibular 

 symphysis, so that the characters are so far those of the other species referred to here. 

 The elongation of the maxillary tooth is more conspicuous than in the P. brachyops. 

 In general this tooth is not absolutely very large, but the teeth anterior and posterior 

 to it are small or very small. Besides the usual series of teeth on the maxillary bone, 

 there are two or more series adjacent. In like manner on the mandibular, besides 

 the dentary series, there are two or three series, perhaps on the splenial bone, stand- 

 ing on a ledge on the same horizontal plane as the tooth-bearing edge of the dentary. 

 In this genus, and probably in all the members of the family, the palate is roofed 

 over posteriorly by the palatine bones. The pterygoids diverge early from the 

 presphenoid region towards the zygomatic border, as in Batrachia generally. The 

 mandibular articular surface consists of two cotyli placed transversely. The os 

 tabulare is small, and is situated, as in other genera of the family, near the posterior 

 junction of the supramastoid and supratemporal. The supraoccipital forms a 

 narrow strip of the posterior border of the superior plane of the skull. The arrange- 

 ment of the cranial bones is as I have described in the genera Isodectes and Pantylus, 

 except that the prefrontal and postfrontal bones scarcely meet over the orbit, 

 instead of separating the orbital border from the frontal. The occipital condyle, 

 as in Empedias, is prominent, and has a median fossa. 



"In Pariotichus aguti the vomers are elongate posteriorly and the palatines 

 send an acute anterior process between them. The palatines are separated by a 

 fissure which is narrow anteriorly and becomes wider posteriorly. Each interior 

 border bears on its posterior two-thirds a row of small teeth. In this respect this 

 genus differs from Empedias, where the palatines are closely appressed on the 

 middle line. The suture between the palatines and the ectopterygoid is not easily 

 made out, but this region descends below the maxillaries to opposite the middle of 

 the inside of the mandible, as in many Lacertilia. Just anterior to the oblique 

 angle which marks this descent a ridge of the palatines extends forwards and out- 

 wards, and for a short distance bears a row of teeth. These teeth, like those of the 

 internal palatine series, are in a single row, differing in this respect from the species 

 of Pariasaurus, as described by Seeley, where they are in two rows, The positions 

 of the rows are the same in the two genera. The posterior border of the (r) ecto- 

 pterygoid supports a patch of teeth in several rows. They are much less developed 

 in Pariasaurus. 



"The pterygoids are slender and diverge from the interior part of the palatines 

 outward, backward and upward, to the inner side of the quadrate. They bear no 

 teeth. The sphenoid is deeply grooved on the middle line, as in Elginia. Its lat- 

 eral inferior keels project below the plane of the short basioccipital. There is no 

 evidence that any of the rows of teeth of the upper jaw rise from the palatine bone; 

 they appear to be maxillary in attachment. 



"The specimen of Pariotichus aguti, on which the above observations are made, 

 possesses, attached to the skull in nearly normal relations, seven vertebrae, a good 

 deal of the scapular arch, and the right humerus. The fifth and sixth vertebrae 

 have slender cervical ribs. The bodies of these, with that of the seventh, are the 



