2 Hatcher — New Dinosaur from Colorado. 



medially by an elongated foramen. Pubic foramen large and situated 

 some distance from the supero-internal border of the bone. Neural 

 arches in dorsal vertebrae extremely high as compared with depth of 

 centra or height of neural spines. Cervicals strongly opisthoccelus, and 

 dorsals only moderately so and becoming almost, platyccelus in the pos- 

 terior dorsal region. Transverse processes of dorsal vertebrae extending 

 obliquely upward and outward from summits of neural arches. Caudal 

 centra short and somewhat amphiccelous with neural spines simple, low, 

 and much compressed. Transverse processes of caudals each consisting 

 of a simple, slender process which in the anterior caudal springs from 

 the side of the neural arch. Posteriorly the transverse processes rapidly 

 decrease in size and assume a more inferior position, so that in the twelfth 

 caudal they are reduced to a rounded knob of bone on the side of the 

 centrum, and in the succeeding caudals they have disappeared altogether. 

 The centra of the anterior caudals are subcircular in outline, but in the 

 posterior caudals the vertical diameter mvich exceeds the transverse. 



The femur is rather longer than one might expect, considering the 

 size and proportions of the individual vertebrae, but does not differ 

 materially from that bone in other genera of the Sauropoda. 



Haplocanthv s may be regarded as the most generalized member of the 

 Sauropoda yet discovered in America. That it is a member of the 

 Sauropoda is clearly shown by the structure of the pelvis and by 

 the characters exhibited by the cervical, dorsal and caudal vertebrae. 

 The comparatively simple structure of the individual vertebrae from the 

 various regions of the spinal column form a striking contrast to that 

 complicated system of laminae and buttresses found in the vertebrae of 

 Diplodocus, Brontosuurus, Morosaurvs, and other Sauropods, and indicates 

 that Haplocanthvs was a more primitive form than any of the latter 

 genera. Its affinities are clearly with the Morosauridce and in size it is 

 comparable with the smaller forms of Morosaurus. Its principal skeletal 

 features will be fully described and illustrated in a forthcoming Memoir 

 of the Carnegie Museum. 



