AND KEPTLLIA OF NOETII AMERICA. 



273 



Vertebral centra and arches are not well distinguished in two individuals, but instead, an axial mass ■which 

 may represent chorda dorsalis. In one, three diapophyses are distinctly developed at the sacral region. In a third 

 individual without head or thoracic region, but in which the ribs and hind limbs are similar, as well as the general 

 propoitions, the vertebra} are distinctly ossified ; but its reference to this species is uncertain. 



Remains of both fore and hind limbs are preserved. They are rather stout, not large, and with short pha- 

 langes. The number of these is not distinguishable. 



' Measurements of Limbs. M. 



Length femur. No. 1 O.OGO 



" tibia and fibula, No. 1, ' .050 



" anterior phalange. No. 1, obverse, .0285 



*• femur. No. 2, .060 



tibia and fibula. No. 2, .070 



" femur, No. 3, .052 



" posterior phalange, • .026 



The deficiency of length of the tibia 'in No. 1, is probably due to imperfection of the specimen. There are 

 bones of the fore limbs in No. 2 which are not determinable. The ribs are rather long and rather curved. The cau- 

 dal extremity is not complete, but was evidently well developed. 



M. 



Length from head to femur, 0.0356 

 " head, .0154 



Width " behind, .0175 

 " " interorbital, .0042 



Length of orbit, .0040 



TUDITANUS EADIATUS, Cope, Si). Nov. 



Represented by crania of several individuals, one of which is nearly perfect, and is selected for description ; 

 otheis are more or less complete ; and i)resent the prominent peculiarities of the species. 



The marked character of this form is seen in the very anterior position of the orbits and contraction of the 

 muzzle. The orbits are large and separated by a little more than their own diameter ; the posterior border is in 

 front of a line measuring the anterior third of the length to the supra-occipital crest, and nearly at the line marking 

 the fourth of the length to the quadrate region. The posterior outline of the skull is deeply concave, the quadrate 

 angle projecting beyond the occipital condyles, which are themselves quite j)rominent. The osseous segments com- 

 posing the cranium are from the orbital region posteriorly, three median, and four lateral on each side. The supra- 

 occipital is rather small, and is broader than long. Its posterior border is straight, as are the short lateral margins. 

 The anterior suture presents an obtuse angle forwards. A large rhombic plate occupies the parietal region, which 

 is i^robably divided longitudinally by a suture, and represents the parietal bones. It extends narrowing, nearly to 

 the orbits, when the middle line is occupied by the much smaller frontal. The suture between the two is obscure, 

 but seems to form an emargination of the parietals. There is a subtriangular post-frontal which expands posteriorly 

 and is succeeded by a supra-temporal which narrows and becomes acute posteriorly, being wedged between the 

 parietal and what may be an anterior production of the plate representing the epiotic. A very large jugal plate 

 extends from the orbits two-thirds the distance to the extremity of the quadrate, the remaining third being covered 

 by a quadi'ato-jugal. After the jugal the epiotic is the largest of the cranial shields or bones, and sends a prolonga- 

 tion forwards between the parietal and supra-temporal, as well as on the outer side of the latter. 



There is no trace of mucous canals. The sculpture consists of strong ridges radiating and inosculating. 

 Radiation is more uninterrupted on both jugal, supra-temporal and anterior part of epiotic ; in the first, they origi- 

 nate in front of the middle exteriorly ; on the supra-temporal, near the anterior part. The inosculation is honey- 

 comb like on the parietil, supra-occipital and posterior parts of the epiotic. 



A. r. s. — VOL. XV. 3q. 



