818 The American Naturalist. [September 
divisions of the Silurian and Cambrian in the structurally complex 
field east of the Hudson River. (Smithsonian Report for 1888.) 
We fail to see that Mr. McGee sustains the comprehensive claims 
made under the first and second heads. Both departments of geology 
referred to had been fully established prior to 1887 ! 
Fossil Birds from the Equus Beds of Oregon.—In the 
AMERICAN NATURALIST of last April (1891) the present writer invited 
attention to the fact that he had in hand for description a large collec- 
tion of fossil birds from the Upper Pliocene of the Silver Lake region, 
Oregon. A small part of these had been loaned by Professor Condon, 
of the University of Oregon, but the great bulk of the collection 
belonged to the cabinet of Professor Cope, who had with marked 
generosity placed them at my disposal for the aforesaid purpose. 
My labors upon this fine collection have now been completed, and 
the work is ready to be passed into the hands of the printers and 
engravers. The memoir will make a quarto volume of upwards of a 
hundred pages, and is illustrated by four quarto plates, presenting over 
- forty figures of the bones of the new species and genera. 
The present notice pretends to be nothing more than a brief 
abstract, giving a list of the species described, with remarks thereon. 
hose indicated by an * have already been either noticed or de- 
scribed elsewhere by Professor Cope. 
PYGOPODES. 
1. <ichmophorus occidentalis.* 3. Colymbus auritus ? 
2. Colymbus holbellit. 4. Colymbus nigricollis californicus.” 
5. Podilymbus podiceps.* 
LONGIPENNES, 
6. Larus argentatus smithsonianus. 10. Larus philadelphia. 
7- Larus robustus. Sp. nov. 11. Xema sabintt, 
8. Larus californicus ? 12. Sterna elegans ? 
9. Larus oregonus. Sp. nov. 13. Sterna fosteri ? 
14. Hydrochelidon nigra surinamensis. 
STEGANOPODES, 
15. Phalacrocorax macropus.* 16. Pelecanus erythrorhynchus ? 
ANSERES. 
17. Lophodytes cucullatus. 20. Anas carolinensis. 
18. Anas boschas. 21. Anas discors. 
19. Anas americana. 22. Anas cyanoptera ? 




