304 



E. 8. Riggs — Brachiosaurus altithorax. 



by a large foramen which leads to an internal cavity in the 



shaft. 



Measurements. 



Humerus, length parallel to axis 



" greatest breadth of proximal end 



" thickness of head antero-posteriorly 



" least breadth of middle of shaft 



" distance from angle of great tuberosity to uppei 



margin of deltoid crest 



" length of deltoid crest 



Femur, length parallel to axis _. 



" breadth of head and great trochanter 



" breadth at fourth trochanter _ 



" breadth at distal end _. 



" distance from head to upper margin of fourth tro- 

 chanter _ _ 



Coracoid, greatest breadth 



" inferior border to scapular margin __ _ 



" glenoid margin to foramen 



Presacral I , length of centrum 



" I, breadth of centrum _ 



" VI, length of centrum _-.._,._ 



" VI, breadth of centrum 



Sacrum, breadth at second transverse process _ 



" breadth at fourth transverse process 



" length of the four centra _. 



Thoracic rib, length _ 



" breadth across capitulum and capitellum 



1 1, height over all _ 



" transverse breadth of centrum ^ 



" length of centrum 



" height of spine above centrum . 



" height of spine above zygapophyses . _ 



Caudal 



M. 

 04 

 65 



28 

 24 



51 

 24 



03 

 59 

 43 



58 



78 



87 



54 



34 



39 



37 



43 



35 



12 



88 



975 



745 



54 



60 



32 



155 



32 



18 



Relationships. 



There have been four genera referred to the Sauropoda 

 whose validity may be more or less called in question. These 

 are Atlantoscmrus and Apatosaurus Marsh, and Oamarasau- 

 rus and Amphicoelias Cope. Some of 'these genera are cer- 

 tainly valid, others probably synonyms. The fact that three 

 of the four are based upon scattered parts of skeletons of which 

 no two have enough in common to make correlation certain, 

 complicates the problem. Added to this is the uncertainty as 

 to whether the type specimens represent one individual or more 

 than one. 



The genus Camarasaurus has usually been regarded as valid 

 and as representing an extreme Morosauroid type. This con- 



