MiscellanpoHs. 179 



chia, but which also exists, according to Giinther, in the living 

 Rhynchocephalous lizard the Sjjhenodon of Xew Zealand. The 

 bones of the limbs and scapular arches are so decidedly reptilian, 

 and so unlike those of any Batrachia Avith which we are yet ac- 

 quainted, that I am disposed to refer them to the former class. And 

 as there are several points in which the fossils resemble the order 

 Rhynchocephalia, I refer them provisionally to that neighbourhood. 

 They constitute the first definite indication of the existence of animals 

 of that type in the western hemisphere. 



Associated witli these saurians were found teeth of two species 

 of fishes, which are important in evidence of the position of the beds 

 in which they occur. One of these is a new species of Ceratodus, 

 Agass., and the other a Diplodus. The former genus is characteristic 

 of the Triassic period in Europe, one species having been found in 

 the Oolite. It still lives in Korth Australia, In both these respects 

 the Khynchocephalian lizards present a remarkable coincidence. 

 They also belong to the horizon of the Trias in Europe ; and the only 

 living species is found in Xew Zealand. Thus it would seem that a 

 fragment of this fauna, so ancient in the northern hemisj^here and 

 80 remarkably preserved in the southern, has been brought to light 

 in IlUnois. It must be added, in reference to the geological age of 

 the fossils, that the genus Diplodus, Ag., has not yet been discovered 

 above the Carboniferous, and that one genus of the Ehynchocephalia 

 belongs to the Permian in Germany. We therefore await further 

 material before venturing to decide whether they belong to Triassic 

 or Permian time. 



Cricotus heterocUtus, Cope. 



Generic characters. — This genus is indicated primarily by caudal 

 vertebrae ; other parts of the skeleton found with it probably belong 

 to the same animal : so I describe them in this connexion, awaiting 

 further discoveries to confirm or disprove such reference. The pieces 

 include parts of two femora, of tibia ?, ulna ?, metapodial and pha- 

 langeal bones, libs, and other pieces. 



The caudal vertebra best preserved is stout, discoidal in form, and 

 deeper than wide. It resembles in form that of an herbivorous 

 Dinosaurian, but differs otherwise. The articular faces are deeply 

 concave, the posterior most strongh' so ; and the middle is occupied 

 by a large foramen, whose diameter is about equal to that of the 

 centrum on each side of it. The lateral borders of the posterior 

 articular face are expanded backwards, and articulate with a bevel 

 of the corresponding edge of the anterior articular extremity. In 

 this way the vertebra combines the mechanical relations of the bi- 

 concave with the opisthoccclian structures. The neural arches are 

 narrow and directed backwards ; their bases are firmly coossified 

 with the centrum ; no zygapophyses appear on the portion of the 

 neurapophyses preserved ; and it is probable that they were weak if 

 existing. On the inferior surface of the centrum two shallow pits 

 occupy considerable space, and indicate the existence of large, free 

 chevron bone.s. No transverse processes. In one vertebra the floor 



