1877.] ^45 [Cop6. 



Total elevation of vertebra 1 . 100 



Length, of neural spine 600 



Elevation of anterior zygapophyses 500 



f antero-posterior 160 



Diameter of neural spine ) transverse (at middle) 065 



(_ " at summit 140 



Depth, of centrum below pneumatic foramen 120 



Fore and aft diameter of pneumatic foramen 080 



Length of pubic bone 1.060 



Thickness of stoutest extremity 140 



Length of femur 1.524 



Transverse extent of proximal end 420 



" " " condyles 320 



Diameter of middle of shaft 220 



Distance from head to third trochanter 665 



Diameter of head (compressed) 260 



Amphiccelias laths Cope. 



Paleontological Bulletin, No. 27, p. 4. 



Of the wonderful fauna of the Dakota epoch of the Rocky Mountains 

 the Oamarasaurus supremus was preeminent in general proportions, the 

 AmphicaiUas alius was the tallest, and the saurian now to be described, was 

 the most robust. It is represented in Mr. Lucas' collection by a right 

 femur and four caudal vertebrae which are in good preservation. They reveal 

 the existence of another saurian of huge dimensions, and of great mass in 

 proportion to its height. 



The caudal vertebrae are apparently from the anterior part of the series. 

 They are all strongly bi-concave ; the anterior face more so than the pos- 

 terior. They all possess diapophyses of depressed form, which take their 

 origin below the base of the neural arch. The centr^are short in antero- 

 posterior diameter, and do not present lateral angles. They are composed 

 of not very dense osseous tissue. The anterior zygapophyses are rather 

 elongate, and their articular faces are directed steeply inwards. They are 

 received by corresponding shallow excavations, one on each side of the pos- 

 terior base of the neural spine. The neural spines are compressed and 

 straight, and become very robust towards the apex. 



The femur is extraordinarily robust. The great trochanter is low, but the 

 shaft is widest where it expands outward. The third trochanter is a ridge, 

 is above the middle, and is short and little prominent. It is on the inner edge 

 of the posterior aspect of the shaft, and looks backwards and inwards. The 

 shaft in its present state is compressed so as to reduce the antero-posterior 

 diameter. It is not however crushed or cracked. The condyles have 

 much greater transverse than antero-posterior extent. They are moderate- 

 ly produced backward, and are separated by a deep intercondylar groove, 

 while the anterior trochlear groove is wide and well marked. The inner con- 

 dyle is narrowed posteriorly, while the external one is obtuse and robust. 



