1892.] Geology and Paleontology. 757 
two additional forms are describéd, and rectifications of synonomy are 
made. 
MANosPONDYLUS GIGAS.—Gen. et sp. nov. Char. Gen.—Dorsal 
vertebree with short anteroposterior diameter, and gently concave 
articular faces. Neurapophyses codssified. At the superior part of 
the centrum, a deep entering fossa ; surfaces of circumference otherwise 
uninterrupted. Tissue of centrum at borders of articular faces 
coarsely vesicular. The form of these vertebrz indicates that this 
genus is allied to the Agathaumide rather than the Hadrosauride. 
No genus of either family known to me possesses the fossæ at the base 
of the neural arch. 
Char. specif—Dorsal centrum a little deeper than wide. Lateral 
surfaces smooth. 
Diameters of centrum. mm. 
: : vertical 205 
Articular face i arate eee 200 
Two dorsal vertebræ are the only remains which I can refer to this 
species, which is the most gigantic of the Dinosauria of the Laramie 
known to me. In the same neighborhood, but several hundred yards 
distant, I discovered a huge supratemporal bone, which differs from 
those of some of the allied genera in having a simple undulate free bor- 
der, without tuberosities or processes. Its form is similar to that of 
Agathaumas, i.e. as broad as long posterior to the quadrate suture. 
There is no evidence that it belongs to this species. 
CLAORHYNCHUS TRIHEDRUS—Gen. et. sp. nov. Char. Gen—This 
genus is established on a rostral and predentary bones of a species of 
the Agathaumide, which were found together and with the fragments 
of a massive supratemporal hone. They are distinguished by their 
absolutely flat inferior faces, there being no alveolar ridges as in the 
forms described by Marsh. They are not compressed but are as wide 
_aslong. They are not adapted to the muzzle of Monoclonius, where 
the rostral bone is compressed. (M. sphenocerus.) 
Char. specif—Rostral and predentary bones as wide as long, with 
flat inferior face and rounded superior median angle. Transverse 
diameter rather exceeding the vertical. Sides convex. All the sur- 
faces furrowed by coarse grooves which terminate in foramina. 
The short wide form of this species differs from that seen in the 
species of the family Agathaumide which have been yet described. 
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