RICHARDSON'S DUSKY GROUSE. 157 



the Platte to the Liard River, a tributary of the Macken- 

 zie. When the ranges of the two species are fully denned, 

 he thinks the T. richardsoni will be found the more north- 

 ern bird. 



The eggs of Tetrao richardsoni are veiy similar, except 

 in size, to those of the obscurus, resembling them closely in 

 their ground-color, as well as in their markings. In the 

 specimens in the Cabinet of the Boston Natural History 

 Society the spots are smaller, a little less distinct, and less 

 numerous. The eggs are 1.75 inches in length and from 

 1.35 to 1.36 in breadth. Baird, Brewer and Ridgway. 



