1877.] 2d7 [Cope. 



Pneumatarthrus, do not exhibit the cavernous structure above described, but 

 are uniformly spongy interiorly. Omithopsis 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 (Ohondrosteosaurus) has been introduced by Prof. Owen, but he 

 gives no characters, nor points out how it differs from Omithopsis, which 

 it resembles in its cellular structure. 



A short time prior to my publication of the description of the genus 

 Gamarasaurus, 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. To the animal 

 to which the sacrum belonged, Professor Marsh gave the name of Titano- 

 murus 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 Omithopsis 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 vertebrae, with twenty caudals. Both 

 scapulae 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 vertebrae 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 



