No. 4. — Characters and Relations of Gallinuloides wyomingensis 

 Eastman, a Fossil Gallinaceous Bird from the Green River 

 Shales of Wyoming. By Frederic A. Lucas. 



The specimen upon which the following observations are based was 

 discovered in the Green River Shales (Middle Eocene) of Fossil, 

 Wyoming, during the summer of 1899, and was shortly after procured 

 for the Museum of Comparative Zoology at Cambridge, where it is now 

 preserved (Cat. Foss. Birds, No. 1598). Dr. C. R. Eastman briefly 

 described (Geological Magazine, February, 1900) the bird as Gallinu- 

 loides wyomingensis, and at his solicitation a more detailed investigation 

 of its structure and relations was undertaken, the results of which are 

 herein set forth. 



Like the well-known Green River fishes, the specimen is very complete 

 and in a most excellent state of preservation, although a little injured 

 as to skull, vertebrae, and digits through the over-zealous preparation of 

 the collector. There is a thin, dark, unctuous layer lying on the same 

 plane as the skeleton and almost confluent with the thinner bones, so 

 much so that in developing the finer points it was at times difficult to 

 shun the temptation to carve out a character that might readily be 

 imagined to exist. This layer obscures the ribs, which are scattered, as 

 well as other portions of the skeleton. While, however, many structural 

 details cannot be made out, the general characters ai'e so distinct and 

 the affinities of the bird so apparent that these defects are of compara- 

 tively small importance. 



The Green River bird was of about the size of a Ruffed Grouse, but 

 stood somewhat higher on its legs. Its galliform nature is obvious at a 

 glance, the most apparent peculiarities being the length of the legs and 

 the depth and the anterior extent of the sternal keel. The majority of 

 its structural resemblances are with the curassows and with the genus 

 Ortalis amongst those birds, but while according to Huxley's definition 

 it indisputably falls in the Peristeropodes, there are sufficiently strong 

 characters to exclude it from both the Cracidse and Megapodiidae. The 

 bird presents no points of affinity with any of the American grouse, still 

 less with any of the Odontophorinoe. 



VOL. XXXVI. — NO. 4. 



