xviii Birds of Colorado 
Arenaria i. morinella, Lophortyx gambeli, Pediocetes 
p. columbianus, Melopelia asiatica, Hlanoides forficatus, 
Ictinia mississippiensis, Astur a. striatulus, Buteo b. 
harlani, Strix varia (breeding ?), S. occidentalis, Crypto- 
glaux f. richardsoni, Conuropsis carolinensis (extinct), 
Coccyzus erythropthalmus, Dryobates villosus, Phleotomus 
p. abieticola, Centurus carolinus, Colaptes a. luteus 
Antrostomus vociferans, Phalenoptilus n.  nitidus, 
Chordeiles a. texensis, Stellula calliope, Myiarchus 1. 
olivascens, Sayornis phebe, Myiochanes virens, Empidonax 
t. alnorum, HE. griseus, Otocoris a. euthymia, Agelaius 
tricolor, Carpodacus purpureus, Loxia  leucoptera, 
Acanthis 1. rostrata, Astragalinus p. mexicanus, Ammo- 
dramus lecontet, Zonotrichia querula, Z. coronata, Z. 
albicollis, Spizella pusilla arenacea, Junco dorsalis, Atmo- 
phila v. scottri, Melospiza melodia, M. georgiana, Passerella 
4. schistacea, Pipilo aberti, Cardinalis cardinalis, Passerina 
cyanea, Pyranga erythromelas, Pyranga rf. coopert, 
Lanivireo s. cassini, Vireo vicinior, Mniotilta varia, 
Protonotaria citrea, Vermivora chrysoptera, Compso- 
thlypis a. usnee, Dendroica cerulescens, D. magnolia, 
D. cerulea, D. striata, D. virens, D. palmarum, Seiurus 
aurocapillus, Oporornis agilis, Wilsonia pusilla, W. 
canadensis, Nannus hiemalis, Cistothorus _ stellaris, 
Hylocichla mustelina, Saxicola cnanthe. 
The vertical distribution of the Colorado birds has 
occupied the attention of many observers; Mr. F. M. 
Drew published in the Auk in 1885 a complete list of 
Colorado birds, as then known, with their vertical dis- 
tribution both in the breeding season and at other times. 
I have confined myself to an analysis of the vertical 
distribution during the breeding season, as the data for 
more detailed study are still very imperfect. In addition 
to this, storms and accidents of various kinds may often 
