1914] Grinndl: Mammals and Birds of tlit Colorado Valley 127 



It will thus be seen that in all essential respects this specimen meets 

 with the description of Falco sparverius peninsidaris Mearns (1892, 

 p. 267), of the southern extremity of Baja California. Mearns 

 expressly states in this connection that all of the sparrow hawks 

 examined bj^ him from the southern borders of California and Arizona 

 are of the large " desert icolus" type. I might dispose of the peculiar 

 Colorado River example by referring it to peninsularis without fur- 

 ther ado. But I do not consider this a reasonable course, unless later 

 acquisition of numerous specimens should show that the sparrow-hawk 

 of the saguaro belt here and that of Lower California is normally 

 like the one in hand and hence different from that of the surrounding 

 regions. This I now doubt, preferring rather to consider the bird in 

 question as an extreme of indi\idual variation in the direction of 

 peninsularis, but to be identified with the obvious geographic stock- 

 form, F. sparverius sparverius (or F. s. phalaena Lesson [=jF. s. de- 

 serticola Mearns] , if a southwestern desert form be considered different 

 from sparverius proper of the north and east). 



There is in the Museum a male specimen (no. 4390) taken by J. G. 

 Cooper at Fort Mohave, December 24. 1860. This may or may not have 

 been a winter \'isitant. But it, too, is small as though possibly repre- 

 sentative of a resident race. It measures : wing 175. tail 111, tarsus 

 31.0, middle toe and claw 31.3. bill from nostril 10.5, culmen from 

 cere 11.1, depth of bill 9.2. In coloration this specimen, also, has the 

 black markings of the mantle reduced to mere indications. 



Pandion haliaetus carolinensis (Gmelin) 



Osprey 



One specimen (female, no 12688) taken April 17 on the California 

 side of the river seven miles east of Picacho. Another seen flying over 

 the river a mile or so above Yuma. May 5. Evidently a migrant 

 through the region. 



Aluco pratincola (Bonaparte) 



Barn Owl 



Feathers of a barn owl were seen on the California side at Eiver- 

 side Mountain. Its presence was nowhere else detected until we 

 reached our last station near Pilot Knob. Here in a low bluff on 



