October 28, 1870.

Prof. B. F. Mudge:

     ESTEEMED FRIEND-The fossils arrived in safety, thanks to the careful packing, and I have examined and determined most of them. The collection is a valuable one, and is an earnest of what can be done for the geological survey of Kansas under more favorable opportunities for collection. I found portions of six species of reptilia, all of the order Pythonomorpha, and five species of fishes, of the new family of Saurodontidæ. Of the reptiles, there were two distorted vertebrae of a large Elasmosaurus, the species not determinable; one vertebra of a large Liodon, probably L. proriger Cope. The limb bones and accompanying vertebrae belong to a Polycotylus (Cope), but whether to P. latipennis is not yet determined. The three other reptiles are quite determinable, and new to science. I have called them Liodon mudgei, after the state geologist of Kansas, Liodon ictericus ( two individuals sent ), and Clidastes cineriarum - the last from the gritty clay limestone [Pierre Shale Formation] near Sheridan [in western Logan County, KS].

     The fishes are quite interesting, and have enabled me to define a new family, and correct the work of Agassiz and Leidy. They belong to the genus Saurocephalus of Harlan [1824], which has been heretofore regarded as a Sphyrænoid fish. I find that it has not the least relationship to that order, but forms a new and interesting group near the Ganoids and Characius. In order to determine it more fully, I am exceedingly desirous of getting more complete remains, especially of the cranium and fins. The following is a list of the species:

Saurocephalus phlebotomus Cope, n. sp.

S. prognathus Cope, sp. nov.

S. napahaticus Cope, sp. nov. [species name from the Nepaholla River, an old name for the Solomon River in North Central Kansas]*

S. thaumas Cope, sp. nov.

This last is the large fish eight feet long without head from 100 miles up the Solomon. Its remains were highly interesting and enabled me to determine many new points in the structure of the group. I found by means of it that the group has a vertebrated tail; also that its anal or caudal fin-ray is that which has always been referred to the Ptychodon genus of sharks by Professor Agassiz.

The pectoral rays have just been described by Leidy as a new genus of catfish, Xiphactinus audax! Then there is a new genus of the same family, Ichthyodectes ctenodon Cope, which is based on jaws and thirteen vertebrae from the yellow chalk. I hope that this species also may at some future time be more fully developed.

I hope these researches, so successfully commenced, may cover the whole vertebrate fauna of the strata, I have studied especially the mammals and birds, as well as the reptiles and fishes. If you desire any part or all of my manuscript for the annual report to the legislature, I will send it on; in the meantime it will appear in Silliman's Journal and some abstracts here.