140 BULLETIN OF THE 



mainly on individual variation of this character. The Rocky Mountain 

 form, to which the name of cunicularia lias generally been restricted, is a 

 little larger than the birds from the Plains, their elevated habitat cor- 

 responding to a more northern locality. Specimens were collected the past 

 summer at intervals from Fort Hays to the Salt Lake Basin. After a com- 

 parison of these with authentic specimens of both A. " cunicularia " and A. 

 hypogoza of authors, I find no difference that is constant, except the rather 

 larger size of the Rocky Mountain form, — a diiference that would a priori 

 be expected. 



FALCONIDJE. 



41. Falco peregrinus. A pair of these birds were found breeding on 

 a high cliff near the Saline River, May 29th, the young being then half 

 grown. The nest was placed on an inaccessible shelf of the cliff, and was 

 composed of sticks. The only other instance that has come to my knowl- 

 edge in which this bird has used any other nest than the bare ground is 

 that mentioned recently by the Rev. William Jarvis in the " American Nat- 

 uralist,"* where he speaks of a nest found by him in the White Mountains, 

 which was " made of a few dry sticks placed round a hollow on a shelf of 

 the cliff." 



42. Falco sparverius. A few pairs observed nesting in hollow trees. 



43. Buteo borealis. A few pairs seen, and a nest found June 1st, con- 

 taining three fresh eggs. 



44. Circus cyaneus, var. hudsonius. Rather common. 



CATHARTID^h 



45. Cathartes aura. Moderately common. Usually seen in small 

 parties of from three or four to a dozen, about the carcasses of recently 

 killed buffaloes. A considerable number were apparently breeding in the 

 vicinity of some high cliffs on the Saline, but a careful search for their 

 nests was unsuccessful. 



COLUMBIDJE. 



46. Zenaeduia carolinensis. Common everywhere, but most numer- 

 ous in the vicinity of timber. Very commonly met with in pairs, many 

 miles from the nearest timber. Many nests were found at Fort Hays, in 

 the timber along Big Creek. Most of them were built in the usual way, 

 forming such slight structures that the eggs could be readily seen through 

 them from the ground. Several pairs, however, were found occupying de- 

 serted nests of the purple grackle, which they had slightly repaired. In one 

 case a nest with two eggs was found on /In' ground, only a few yards from 

 shrubs. From the frequency with which I had seen pairs of these birds far 

 out on the plains in the nesting season, T was led to anticipate this method 



* Am. Nut., Vol. V, [>. CG2. 



