Z 
564 tee General Notes. [June 
propodial bones. In the Polycotylinz they are wider than long, 
and angular in form, resembling those of Ichthyosaurus. In the 
Plesiosaurine they are well-differentiated elements, as in Mosa: 
saurus, or marine turtles. There are two genera of Polycoty- 
line, both American, as follows: 
Neurapophyses and all diapophyses and parapophyses 3 
coéssified with vertebral centra Polycotylus. 
Neurapophyses and other processes articulating freely 
with centra 
Piptomerus. 
Of these, Piptomerus is represented by numerous remains in 
the Fox Hills beds of New Mexico. ther species occur, which 
present the following characters: 
Neural arches loosely articulated ‘ Plesiosaurus. 
Neural arches codssified, parapophyses free................. Orophosaurus. 
th neural arches and parapophyses codssified Uronautes. 
Of these genera, Uronautes has been previously obtained in 
the Fox Hills bed of Montana. The probable character of the 
scribed is adult, the two genera are quite distinguishable. The 
other characters of the genera and of the species are as follows: 
Liptomerus Cope, g. n.—Cervical vertebre short, slightly bi- 
concave; dorsal vertebre very short, nearly amphiplatyan; nu- 
tritive canals many, large. In the known species the articular 
surface is reflected on the sides of the centrum, so as to restrict 
the width of the dense layer. In the known species there is 
pophysis in the cervical vertebre. Free extremities of para- 
d. 
eae ph 
tural surfaces of articular fosse generally not roughened. Dor- 
sal centra much compressed ; neurapophysial fossa very oblique, 
* Quarterly Journal Geological Society London, 18 4, P- 436. 
Soc eadings Academy Philada., 1876, p. 345. isco 
