Mc 
1871.} 267 [Cope. 
* 
and somewhat contracted, and marked everywhere with finer and coarser 
strie. Hypapophyses prolonged on the cervicals, the free one of the 
atlas with a prolonged keel-like process. 
Quadrate bone with long external angle and rather thick anterior ala 
with broad rugose margin. A prominent obtuse ridge is continued from 
the external angle to the inferior articular extremity, the distal portion 
being more acute. A rugose process projects at the point where the pos- 
terior hook approaches the body, and is continued as an elevated narrow 
ridge, parallel to the previously mentioned, to the distal articular surface. 
A. button-like knob appears on the posterior margin of the hook opposite 
the meatal part. A. strong ridge extends on the inner face of the bone 
from opposite the end of the hook to the base of the great ala. The 
distal articular surface presents two planes ; the narrower at the end of 
the posterior pair of ridges above described ; the larger considerably less 
distal, like a broad step. 
The maziilary bone descends regularly in front, uniting with the pre- 
maxillary by a minute suture. Its posterior extremity is slender and acute. 
The premaxillary is short conic, not particularly prominent. The 
palatine bone has a slight expansion on the inner side ; on the outer the 
margin is very narrow. 
The teeth number seventeen on the maxillary bone. They : 
pressed, least so anteriorly, and with a cutting edge from base t 
as far as the fifth from the front, in those anterior to that point the pos- 
oid teeth which are 
‘e com- 
0 crown 
terior edge is discontinued. There are sixteen pte1 
smooth and without anterior cutting edge. The frontal bone has a low 
carina along the median line of its anterior portion. 
M. 
Length of axis with odontoid proces ite. 
Diameter of ball of a cervical f vertical ae -026 
Uiramis verse: 7, bse 026 
Hixpanse of diapophyses do. 3.22.4. 22.2000.7 = ed 084 
Length of centrum Or. eae PO 052 
Length oimaxillary bone. .4e ue eee 363 
- ramus mandibuli behind dentary.............. 3B 
Length of prem 
Total of cranium 
Length of pterygoid and palatine .015 
8 ] 18 
Length of centrum posterior do -066 
‘ WOMLIONL. 6 Ee es .088 
Diameter of ball , 
LYATISVOESG direc SAL fades acs .038 
The bones of this species are all light and slender. The elongation of 
the vertebre indicate that if their number was of the usual amount, the 
animal was of more than usually slender proportions. The position in 
which it was found was a partial coil, the head occupying the inside of a 
turn of the dorsal vertebra. As compared with H. dispar and ZH. veloz of 
Marsh, the present differs in the lack of depression of the centra of the 
