GEOLOGICAL PAPERS. 97 



shape, slightly recurved, with round, indented knobs at the ends. 

 The first pair are about three inches long, and gradually decrease in 

 size as they ascend. 1 call this animal "the ladder-spined reptile." 

 I am told that Professor Cope believed these spines served as masts 

 and yard-arms, from which were stretched membranous sails which 

 enabled them to catch the breeze and tack along the surface of the 

 ocean. Possibly, as the vertebrae are small and the spines extremely 

 slender, these lateral processes gave stability, when securely bound 

 by strong ligaments to the flesh on the column, preventing disloca- 

 tion. I have found many fine specimens of this remarkable reptile. 

 One found this year rejiresented parts of the upper jaws. A huge, 

 massive bone projects beyond and below the huge tusks in the lower 

 jaws, bent in a curve, presenting a unique appearance, for what pur- 

 pose I can hardly guess, unless to give rest to the head while sleep- 

 ing. But time would fail me to tell even in this cursory manner of all 

 the strange life preserved for us of these ancient mariners who lived 

 in the water or along the swampy shores of the Permian ocean. How 

 those ancient frogs must have tortured the ear of night on a warm 

 summer evening ! 



I must now turn a short time to the rock formations, of which there 

 are two distinct ones in the valley of the Big Wichita, in Texas, which 

 give characters to the surface of the country, as different from each 

 other as if separated by hundreds of miles. I visited one locality on 

 Pony creek where the Red Beds lie on top of the Gray Beds con- 

 formably. Looking to the west, a vast panorama of crumbling and de- 

 nuded bluffs, narrow valleys, beetling crags, desolate and forlorn, with 

 the universal red color dominating everything, except here and there 

 relieved by the green of stunted mesquites or patches of verdure, was 

 spread out before me. To the east lay the narrow valley of Pony 

 creek, with the same topography so familiar to the residents of east- 

 ern Kansas — a ledge of gray sandstone, forming a narrow escarpment 

 on either side, and following the trend of the hills around the ravines ; 

 grass coming down in gentle swells to meet it, or running up from the 

 bottom lands below. The greatest thickness of this sandstone, as I 

 observed it, was near my camp in the creek bottom where I had pitched 

 it, eight miles north of Seymour, the county-seat of Baylor county. 

 This was at the head of a narrow gulch that had cut through it. I 

 made a section and sent samples of the rock to Munich. As I ob- 

 served it under peculiar circumstances, it solved another interesting 

 problem — the water-supply of the Red Beds. I discovered why the 

 water that falls where these beds are only exposed runs off soon after 

 a shower, except when caught in natural or artificial tanks. No wells 



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