134 



SCIENCE 



[N. S. Vol. XL. No. 1021 



DISCUSSION AND CORRESPONDENCE 



NOTES ON THE FOSSIL VERTEBRATES COLLECTED ON 



THE COPE EXPEDITION TO THE JUDITH RIVER 



AND COW ISLAND BEDS, MONTANA, 



IN 18T61 



As I was Professor E. D. Cope's assistant 

 on the above expedition, and as sucla diverse 

 opinions are held regarding the stratigraphy 

 of this Montana district, I have thought it of 

 interest to try and disentangle the muddle, and 

 to show that the Montana beds are to be corre- 

 lated with those of Bed Deer Eiver, Alberta, 

 on the evidence of their vertebrate fossils. 



The following list gives the species collected 

 by us in 1876, and described by Professor 

 Cope, in camp on Dog Creek, four miles east 

 of Judith Eiver. I mention only the speci- 

 mens I remembered positively, and collected 

 (or handled), from the top of the " bad-lands " 

 on Dog Creek. We were camped on the nar- 

 row flood plain, and every morning at day- 

 break we mountedour horses and climbed to 

 the top of the strata, where our real work 

 began. We passed over what Cope called the 

 Pierre and Fox hills groups of Dr. Hayden, 

 to the latter's typical locality, from which he 

 secured the material described by Dr. Leidy, 

 viz., of Trachodon, Deinodon, Trionyx, etc. 

 We secured many specimens of these types, 

 and many Cope described as new to science. 

 Among them are the following: Myledaphiis 

 hipartitus Cope, Hedronchus sternbergi Cope, 

 Trionyx foveatus Leidy, Trionyx vagans Cope, 

 Compsemys imhricarius Cope, Gompsemys vic- 

 tus Leidy, Gompsemys olscurus Leidy, Deino- 

 don horridus Leidy, Deinodon {Aublysodon) 

 lateralis Cope, Deinodon hayzenianus Cope, 

 Deinodon (Lwlaps) incrassatus Cope, Palwo- 

 scincus costatus Leidy, Dysganus encaustus 

 Cope, Dysganus haydenianus Cope, Dysganus 

 hicarinatus Cope, Dysganus peiganus Cope, 

 Trachodon miraUlis Leidy, Diclonius penta- 

 gonus Cope, Diclonius perangulatus Cope and 

 Diclonius calamarius Cope. 



We then followed the prairie forty miles 

 down to Cow Island, and went into camp three 



1 Published witli the permission of the Director 

 of the Canadian Geological Survey. 



miles below the landing on the opposite 

 (south) side of the Missouri Eiver. Here no 

 teeth, fragments of bones nor turtle shells 

 were found on the surface, as on Dog Creek. 

 It was possible to locate the bones in one 

 way only, viz., by noticing the color of the 

 surface dust above the bones, which in all 

 cases differed from that of the surrounding 

 disintegrated rock. By digging beyond the 

 action of the frost we found the following 

 species of Cojpe— Mono clonius crassu^, Mono- 

 clonius spenocerv^, Monoclonius recurvicomis 

 and fissus. The Monoclonius crassus was 

 found by Cope, at least the type; Mr. Isaac 

 also got a crassus. Cope's specimen was found 

 on the south side of the river in the hills about 

 three miles below Cow Island. My specimens 

 of which I got recurvicomis and spenocerus 

 came from the north side of the river about 

 four miles below Cow Island Landing, and Mr. 

 Isaac's a mile farther down on the same side 

 of the river, both near the flood plain. 



I had the pleasure last year, and the year 

 before, of exploring the Edmonton and BeUy •, 

 Eiver series of Bed Deer Biver, Alberta, and 

 to me the succession of the rocks appears to. 

 be the same as in Montana, from the mouth 

 of the Judith Eiver to Cow Island. 



At Dog Creek are the typical Judith Eiver 

 beds of Hayden and Cope, followed below by 

 the Fox-HiU-Pierre, which are in turn under- 

 lain by the Cow Island beds, the Judith 

 Eiver beds correlating with the Edmonton, 

 and the Cow Island with the Belly Eiver 

 series. 



In descending Bed Deer Eiver last June 

 from Drumheller to Berry Creek, a distance 

 of eighty miles, the Pierre beds were seen ap- 

 pearing from beneath the Edmonton, and the 

 Belly Eiver from beneath the Pierre. 



The evidence of the fossils corroborates the 

 distinction between the Cow Island beds and 

 the Judith Eiver beds at Dog Creek. The 

 trachodonts of the Belly Eiver formation, for 

 instance, are quite distinct from those of the 

 Judith Eiver and Edmonton. Take, for ex- 

 ample, Gryposaurus notabilis Lambe, with its 

 short heavy skull, high quadrate and elevated 

 Again the resemblance of the Belly 



