GEOLOGICAL PAPERS. 123 



PROTOSTEGA GIGAS AND OTHER CRETACEOUS REPTILES 

 AND FISHES FROM THE KANSAS CHALK. 



By Chaeles H. Steenbeeg, Lawrence, Kan. 

 Read before the Academy, at Manhattan, November 27, 1903. 



IN his report to the United States Geological Survey of the Territories, 

 volume II, 1875, Prof. E. D. Cope fully describes the material on 

 which he founded the new genus Protostega. To me, after all these 

 years, having collected many specimens of this large tortoise, it has 

 been a wonder how he was able, from the bones he collected himself 

 and restored with infinite care and patience, to make such a nonde- 

 script of the animal, especially as in volume IV he gives, as the 

 most important law that governs paleontology, "the persistence of 

 type." But this creature, as he created it, is an exception to the rule. 

 He makes the total length 12.83 feet, with width of carapace 

 three feet and length seven feet, or twice as long as wide. One mis- 

 take leads to another. The professor thought the skeleton he discov- 

 ered lay on its back. The loose ribs doubtless did, as their heads were 

 pointed upward. During the time it was being buried in the soft 

 sediment they could easily have been turned over. I have found hun- 

 dreds of specimens where the elements have been macerated free from 

 their fellows, and lying in every conceivable position ; in fact, it is 

 rare indeed to find them in their natural position. With this idea 

 firmly fixed, he proceeds to put the great radiated bones of the plas- 

 tron in the skin of the back as "lateral dermal plates," along with 

 some of the bones that cover the top of the skull. In describing the 

 plates, he notices they were concave on the under surface, yet the ribs 

 were flat and straight. It is useless to try and understand how he 

 could have made such mistakes when he had so much of the skeleton 

 present. For many years his description remained uncorrected, though 

 in 1876 my party sent him a nearly complete skeleton. 



Prof. E. 0. Case, in his paper on the 'Osteology and Relationships 

 of Protostega,'' published in 1897, is so fortunate as to have for 

 description an almost complete plastron with marginal plates. Of 

 course. Cope's "lateral dermal plates" are no more, as Case finds them 

 in the plastron. He is therefore able to give the correct proportions 

 of the under joart of the body. The carapace and limbs in correct 

 position are unknown to him. I was so fortunate as to discover a 

 nearly complete skeleton of this tortoise last summer in Logan county, 

 Kansas. The arches, limbs, and most of the column and ribs, I have 

 the pleasure of exhibiting to you. It has taken me over a month to 



