426 Eaton — John Day Felidce in Marsh Collection. 



must be limited, in the main, to a discussion of the 

 osteology and affinities of the material examined, and 

 less attention can be paid to stratigraphic considerations 

 than would otherwise be desirable. Yet notwithstanding 

 real or suspected shortcomings in field work during 

 pioneer days, the fact remains that this material, collected 

 half a century ago, is worthy of careful study, and con- 

 tains forms specifically distinct from those previously 

 described. It is a pleasant duty therefore to express 

 the admiration that is felt for the generous enthusiasm 

 that led Professor Marsh to be one of the first paleontolo- 

 gists to visit the John Day Valley and to encourage the 

 search for fossils in that region. 



Tables. — For convenience in comparing the new 

 species, here described, with the earlier types, cranial 

 measurements have been arranged in parallel columns in 

 Table A (page 442). While most of the measurements, 

 selected for this purpose, conform with those used by 

 previous authors, three new measurements have been 

 introduced, and an external palatal length has been 

 substituted for the old mid-line measurement, This 

 table as originally constituted included practically all 

 the measurements of, cranium and mandible used by 

 Merriam and by Thorpe ; but while extremely useful in 

 the study of material in the laboratory, it was thought 

 too large for convenience of publication at the present 

 time. The table has therefore been cut down to about 

 one third of its original size by the omission of all mandi- 

 bular and nearly all dental measurements, as well as of 

 several cranial measurements that, on trial, did not yield 

 satisfactory differential indices. Although the number 

 of measurements and indices has been reduced, it has 

 seemed desirable that the series of specific types, and 

 other crania, tabulated under the several genera, should 

 be as complete as possible, in order that the range of the 

 indices characterizing these genera might be reliably 

 determined. For this purpose four of the best preserved 

 crania of the genus Nimravus in the Marsh Collection 

 have been measured and the resulting indices recorded. 

 Examination of several of Cope's types, now in the 

 American Museum of Natural History in New York, 

 has been possible through the courtesy of Dr. W. D. 

 Matthew of that institution: and Professor John C. 



