658 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



List of specimens. 



PODILYMBUS PODICEPS, {Linn.) Latvr. 



Dabchick. 



Observed in the same situations as the last two species, but less fre- 

 quently than either of them. Chicks still unfledged were taken so late 

 iis August 7. The streaking of the head of the young bird, supposed 

 to be peculiar to this species, and once made the basis of a new species, 

 is shared by others, as P. cornutus, for example. 



List of specimens. 



BIBLIOGRAPHICAL APPENDIX. 



Besides the several general works on North American Ornithology 

 which bear in due part upon the Birds of the region surveyed, the fol- 

 lowing special treatises since Lewis and Clarke, relating to the Avifauna 

 of the Boundary and adjacent portions of the country, may be advan- 

 tageously consulted : — 



1831. Swainson, W., and Richardson, J. Fauna Boreali-Americana ; or the Zoology 

 of the northern parts of British America: [etc.] Part Second, The Birds. 

 By William Swainson, Esq., [etc.] and John Richardson, M. D., [etc.] Lon- 

 don: John Murray. 1831. 4to. pp. Isvi, 524, pis. 24-73, woodcuts 41. 



This remains the standard treatise on the Birds of British America, and is particularly full 

 in accounts of the Ornithology of the Saskatchewan Region. 



1837. Townsend, J. K. Description of Twelve New Species of Birds, chiefly from the 

 vicinity of the Columbia River. < Journ. Acad. Nat. Sci. Phila. vii, 1837, pp. 

 187-193. 



1839. Townsend, J. K. List of the Birds Inhabiting the Region of the Rocky Mount- 

 ains, the Territory of the Oregon and the North West Coast of America. 

 < Journ. Acad. Nat. Sci. Phila. viii, 1839, pp. 151-158. 



