360 University Geological Survey of Kansas. 



lar and more sharply defined, especially at the extremities of 

 the centrum. The neural arches probably fit into pits above, 

 and the ribs seem to have been attached to tubercular processes 

 of bone set into pits, as in the Ichthyodectidse. Those in the an- 

 terior region are very thin, and the pits for the neural arches 

 are large and widely separated. 



Nearly the whole of the scapula is preserved. It shows a 

 large convex superior (?) facet with a smaller one just below it, 

 the two being separated by a sharp ridge. Just back (?) of the 

 larger facet there is a large foramen, the anterior border of 

 which is broken away. 



There is a second specimen of a shoulder-girdle and a mass 

 of fin-rays which probably belong to the same genus as the 

 above, but probably a different species. The chief difference is 

 found in the absence of the small facet on the articular portion 

 of the scapula. At the lower extremity there is a large rough- 

 ened surface that probably unites with the coracoid. The 

 coracoid (?) is a broad, flat plate of bone which is thickened 

 at the posterior extremity and presents a roughened articular 

 surface for the scapula. The cleithrum is too fragmentary to 

 determine its exact form, but it was probably concave on the 

 internal (?) side and somewhat irregular and roughened on the 

 external. 



The proximal portions of the fin-rays of both sides are pres- 

 ent. They are large and very numerous, fourteen being pres- 

 ent on one side, and this probably does not represent all of 

 them. The larger of these are slightly bent at the proximal 

 extremities, and the smaller ones strongly so. 



Lower jaws of Pachyrhizodus minimus, one-half natural size. 



