REFT I LI A: LIMNOSCELIS 27 



the interior one on the right side had been lost before fossilization, 

 but its mate is complete; the second and third teeth are succes- 

 sively smaller, but of the same character as the inner one, long, 

 conical, and recurved. The bases of two are present on one side, 

 with indications in the matrix of their length. Doubtless when the 

 skull is finally prepared the missing parts will be found. The 

 long tooth lies in the specimen as I have figured it, directed down- 

 ward and backward, and closely apphed to the end of the mandible. 

 The. maxilla has quite the same relations as in the other Ameri- 

 can cotylosaurs where it is known, a rather narrow bone united 

 with the premaxilla below the nares, with the lachr5Tnal through- 

 out nearly its whole length above, and with the jugal posteriorly 

 below the orbit, which it joins by a long, obhque, serrated suture. 

 The precise number of teeth I cannot be sure of. On the left side 

 the teeth are hidden by the obliquely compressed mandibles from 

 the outer side; on the right they are not perfect. Before the parts 

 were cemented together, Mr. Gibb worked out the left maxillary 

 and mandibular teeth from the inner side in large part, and these 

 have been used to complete the figures in the drawing. There are 

 at least twenty in the maxilla, and perhaps more. The anterior 

 ones are longer and stouter, conical like the incisors, and somewhat 

 recurved. Their attachment to the bone is more or less pleuro- 

 dont. The posterior teeth are shorter, but are also nearly circu- 

 lar at their bases. There is but one row. The nasals are very 

 large bones, occupying nearly the whole of the upper surface of 

 the skull in front of the orbits, and are gently convex or fiat. The 

 lachrymals, as in probably all Cotylosaurians, are elongate, form- 

 ing the posterior border of the nares and a part of the anterior 

 border of the orbits. As in the Diadectidae, and quite unlike the 

 condition in the Pariotichidae, the small frontals do not take any 

 part in the orbital border, which is formed by the prefrontals and 

 postfrontals; as in the Diadectidae, both these bones are short 

 and broad, reaching scarcely beyond the orbit in front or behind. 

 The parietals are short, broad bones forming most of the superior 

 surface of the skull back of the orbits; the parietal foramen is of 

 the usual size, very unlike the enormous one of the Diadectidae. 

 The sides of the skull back of the orbit are formed chiefly by the 



