PERMO-CARBONIFEROUS VERTEBRATES FROM NEW MEXICO. 4 1 



These relations are proven incontestably by material in the collections of the 

 University of Chicago, and Williston vouches for them. The best evidence we 

 have seen of the presence of a lateral quadratojugal bone in any pelycosaurian 

 reptile is that furnished by the present specimen. 



The posterior thickened border of the quadrate slopes obliquely backward 

 from the long axis of the skull. How much of the quadrate is actually visible 

 from without, how much is covered by the roof bones, can not be said. There 

 is certainly no quadrate foramen. 



The face in front of the orbits, as has been said, is of great extent. Sutural 

 lines can not be detected, though the longitudinal striation of the broad, long, 

 and somewhat thickened nasals indicates their width, and probably their length, 

 reaching far back toward the orbits. The prefrontal seems to be large, and the 

 extent of the jugal seems to be indicated by striation and sutural lines. Whether 

 the lachrymal (postnarial) extends the whole distance to the margin of the naris, 

 as in the cotylosaurs, is doubtful ; certainly if it does it must be a very slender bone. 



The maxilla is a very long bone, with its dentigerous border somewhat thick- 

 ened and convex in outline. Twenty-nine maxillary teeth are preserved, with 

 vacant spaces for six or seven more, which, if present in life, must have been lost 

 before fossilization. Possibly the whole number of teeth in this bone may have 

 been 36. The teeth are slender, conical, recurved, and pointed, and they do not 

 vary much in length as far back as the middle of the series. At about the junction 

 of the first and middle thirds of the series there is a distinctly stouter tooth, corre- 

 sponding to the large maxillary tooth of Varanosaurus. The maxilla is thickened 

 above it, and the dentigerous border here is more convex or subangular in outline. 

 The teeth extend posteriorly to opposite the lower angle of the orbit. In the 

 mandible, so far as can be observed, the teeth are all uniformly slender, especially 

 the more anterior ones, with the exception of the first one or two, which seem to 

 be stouter. In the premaxillze there are three teeth on each side, all larger than 

 the ones immediately following in the maxilla; the foremost is perhaps as stout 

 as the enlarged maxillary tooth. 



The mandible is long and slender, with a marked concavity of its alveolar 

 border corresponding to the convex dentigerous border of the maxilla. The man- 

 dible is a little thickened in front, where the two sides meet in a short symphysis 

 about an inch in length. The coronoid angle is not high ; its border is gently convex 

 above, where it slightly underlaps the free border of the quadratojugal. In the 

 space left free back of the teeth, between the jugal and the mandible, the rather 

 broad surface of the pterygoid, or ectopterygoid, is visible ; the bone clearly abutted 

 against the mandible in life. As regards the structure of the mandible little can 

 be said, save that the very long splenial meets its mate in a symphysis, as is usual 

 in the early reptiles. 



The present specimen seems to demonstrate, for the first time in a Paleozoic 

 reptile, the normal presence of both supratemporal and lateral temporal fenestras.* 



* Neither of us is quite convinced of the presence of both vacuities in the Proganosauria and Protero- 

 sauria. The presence of the upper vacuity in Paleohatteria has been, we believe, assumed because of the 

 resemblances otherwise of that genus to Sphenodon. Credner, in his original description of the genus, 

 alludes very briefly to its presence as "wahrscheinlich"; apparently no certain evidence of its existence 

 was found in any specimens which he studied. In a later paper he restores the skull after Sphenodon and 

 says the vacuity is present, but gives no reasons for this statement. We have seen that other Permian 

 reptiles having like "rhynchocephalian" characters do not have two vacuities on each side, and the pres- 

 ence of an upper one in Paleohatteria must remain a subject of legitimate doubt until additional evidence 

 incontestably demonstrates its presence. A very recent examination of the type specimens of Paleohatteria 

 in Leipsic has convinced Williston that only one temporal vacuity is present. 



