1877.] 237 [Cope. 
Pneumatarthrus, do not exhibit the cavernous structure above described, but 
are uniformly spongy interiorly. Ovnithopsis of Seeley, which Owen refers 
to his subsequently described Bothrospondylus, possesses a cavernous cellu- 
lar structure, which I have not found in the reptile from Canyon City, 
Colorado, but which occurs in the huge saurian discovered by Prof. Lakes, 
near Golden, Colorado, in the same stratigraphical horizon. Another 
name (Chondrosteosaurus) has been introduced by Prof. Owen, but he 
gives no characters, nor points out how it differs from Ornithopsis, which 
it resembles in its cellular structure. . 
A short time prior to my publication of the description of the genus 
Camarasaurus, Prof. O. C. Marsh of New Haven issued a description of a 
portion of a sacrum of a saurian found in the Dakota beds near Morrison, 
Colorado, a point one hundred miles north of Canyon City. Tothe animal 
to which the sacrum belonged, Professor Marsh gave the name of Titano- 
saurus montanus. As the name of the genus was not accompanied by 
any generic diagnosis or specific reference to its characters, it has no claim 
to adoption according to the rules of nomenclature, nor is the genus 
distinguished from some of those above enumerated. Especially is there 
nothing to indicate that it differs from Ornithopsis or Bothrospondylus. 
The name given has also been already employed by Dr. Lydekker of the 
Geological Survey of India. 
CAMARASAURUS SUPREMUS Cope. 
Paleontological Bulletin, No. 25, p. 7; Aug. 1877. 
The bones of this species so far discovered by Mr. Lucas are:—a cervical 
and twenty dorsal and lumbar vertebre, with twenty caudals. Both 
scapulz and coracoids were recovered, with one-half of the sacrum, and two 
pairs of pelvic bones. Of the hind limb I have the femur, with a tibia less 
certainly belonging to the same animal, although found among the other 
bones. There is one metapodial. There are many other bones which I 
have not yet reconstructed or determined. 
The dimensions of this animal may be inferred from the fact that the 
cervical vertebra is twenty inches in length and twelve in transverse diame- 
ter; and that one of the dorsals measures three and a half feet in the spread 
of its diapophyses, two and a half feet in elevation and the centrum thirteen 
inches in transverse diameter. Another dorsal is two feet ten inches in ele- 
vation. The scapula is five and a half feet in length and the femur six feet. 
The centra of these vertebre bear a ball and socket articulation of the 
opisthocoelian type, the cups and balls being well pronounced ; just be- 
neath the diapophysis is situated a huge foramen. A broken centrum 
from which Mr. Lucas removed the matrix, shows that this foramen com- 
municates with a huge internal sinus, which occupies almost the entire 
half of the body of the vertebra. Those of opposite sides are separated by 
a septum which is thin medially. Thus the centra of the dorsals are 
hollow. The neural arches are remarkable for their great elevation, and 
the great expanse of the zygapohpyses. They are more remarkable for the 
