114 Ihe American Naturalist. [February, 



on Buck Creek, some of 35 miles north of Lusk, Wyoming. 

 Early in the spring of 1889 the writer proceeded to Lusk, near 

 which place Mr. Wilson still lived, and easily succeeded in 

 getting that most accomodating gentleman to show him the 

 skull from which he had taken the horns. This has proved a 

 most important locality, and material obtained from it has in- 

 creased many fold our knowledge of the Laramie reptilian and 

 mammalian faunas. In the nearly four years spent by the 

 writer in working these beds, 31 skulls and several fairly com- 

 plete skeletons of horned dinosaurs were secured, besides two 

 quite complete skeletons of hirln n i,ia (( lon.vnrnis), about 5000 

 isolated jaws and teeth of Laramie mammals and numerous 

 remains of other dinosaurs, turtles, lizards, birds and fishes, 

 as well as extensive collections of freshwater invertebrates from 

 the same beds. In all over 300 large boxes of fossils were 

 collected for the U. S. Geological Survey, and are now carefully 

 stored in the Yale Museum, many of them as yet unopened. 



At present remains of horned dinosaurs are known from only 

 four widely separated localities; one of these, that of Black Butte, 

 Wyoming, is west of the main range of the Rocky Mountains, 

 and the other three including the Denver locality in Colorado ; 

 the Converse Co. locality in the extreme eastern portion of 

 central Wyoming, and the Judith River or Cow Island locality 

 in northern Montana, lie east of the main range. There are 

 other localities known to the writer, but they are as yet of 

 minor importance, since little collecting has been done in them 

 and no material has been described from them. They will be 

 referred to later. 



The Ceratops Beds. 



In the American Journal of Science for December, 1889, 

 Professor Marsh applied the name Ceratops beds to certain strata 

 in the west from which horned dinosaurs had been secured. 

 He did not then, nor has he at any time since, designated just 

 what he considered the geographical distribution of these beds 

 nor their upper and lower delimitations in the geological scale. 

 In order that the reader may not be misled in regard to Pro- 

 fessor Marsh's position on this question I will quote him some- 



