288 University Geological Survey of Kansas, 



of bone with a quadrilateral face in front and a small spine pro- 

 jecting upward and backward behind. On the internal side 

 there is a large, slightly concave facet, which has the appear- 

 ance of having been united with a similar bone on the opposite 

 side. All of these vertebrae are curved slightly upward. 



Four of the haemal spines from this region are present in one 

 specimen. The two anterior of these are very similar, being 

 broad, flat, and in contact with each other throughout. At the 

 upper extremity of each there are two large, roughened, sutural 

 surfaces for uniting the spine to the centrum. Between these 

 two surfaces runs the small haemal canal. The one following 

 these two is not so flat but slightly thicker, and has the upper 

 end expanded into a knob-like mass of bone. The articular 

 surfaces have become conjoined and form a saddle-shaped ar- 

 ticulation with the centra, the haemal canal having become 

 somewhat depressed. The spines following this have become 

 modified into somewhat fan-shaped hypural bones. The upper 

 extremities of these present convex condyles, which are proba- 

 bly received into pits on the last two vertebrae mentioned above. 



There is one haemal spine from somewhere in front of the 

 caudal region which is of a different form from those described 

 above. It is a Y-shaped bone with elongated and roughened 

 articular surfaces on each of the arms for uniting it to the cen- 

 trum. The haemal canal is very large and below it the bone is 

 rather thin. 



The caudal fin-rays are represented by a mass of spines, only 

 one of which is complete. The anterior of these are rod-like, 

 but those following become expanded at the upper end, where 

 they are longitudinally striated. These are followed by rays 

 which are broader and probably shorter, on which the striae 

 just mentioned are more pronounced. 



The neural spines are represented, in good condition, by only 

 three or four from just back of the skull, some of which I have 

 been able to fit to the vertebrae to which they belong. They all 

 have knob-like expansions at the lower end which are received 

 in the pits on the top of the centra. The two halves are in con- 

 tact with each other above the neural canal and nearly or quite 



