AVES* 
71 
briefly stated thus : — (1) The Para district belongs to the same 
zoological province as the Guianas^ and has received its birds 
mainly thence. (2) In certain cases (17 per cent, of the Whole 
number, excluding species of general distribution) variation has 
arisen, resulting in the production of new specific forms of greater 
or less distinctness. (3) In some of these cases the Amazons 
has operated as a barrier, isolating the derived forms from their 
Guianan allies, thereby leading to accumulated variations, ulti-, 
mately resulting in the Specific differences now observable. 
ScLATER, P. L., and Salvin, Osbert. Catalogue of Birds col- 
lected by Mr. E. Bartlett on the River Huallega, Eastern 
Peru, with Notes and Descriptions of New Species. Tom, 
cit. pp. 748-759, pi. xxxiv. 
The collection contained nearly 1000 specimens, belonging to 
205 species, and was chiefly made at Yurimaguas, Xeberos, and 
Chyavetas, on or near the river named. Several species are not 
precisely determined ; but only five, belonging to the families 
Picid< 2 , CypsclidcRy Dendrocolaptidmy and Formicariida (2), are 
characterized as previously undescribed, which is probably owing 
to the fact that Mr. Hauxwell collected largely in the same dis- 
trict. 
, . List of Birds collected at Pebas, Upper Ama- 
zons, by Mr. John Hauxwell, with Notes and Descriptions 
of New Species. Tom. cit. pp. 977-981, pi. xlv. 
The list contains 135 species, of which notes are added re- 
specting seven, four of them (belonging to Formicariidoi, Ty^ 
rannid(By Fringillid(B, find Fallidm) being described as new. 
, . On Peruvian Birds collected by Mr. Whitely. 
Part I. Tom. cit. pp. 982-991, pi. xlvi. 
This contains an account of the birds obtained by the collec- 
tor in his expedition to South-western Peru, and includes 58 
species, none of which appear to be new, though several rectifi- 
cations of synonymy are made. 
ANATOMY AND PHYSIOLOGY* 
CouES, Elliott. On the Osteology and Myology of Colymbus 
torquatus. Mem. Boston Soc. Nat. Hist. i. pp. 131-172, 
pi. V. 
A very good monograph, most plainly written. {Cf, Ibis, 
1868, p. 229.) ' 
Eyton, T. C. Osteologia Avium ; or, a sketch of the Osteology 
of Birds. Wellington, Salop : 1867. 4to, pp. 229, pis. 
The publication of this work was commenced in 1858 (Ibis, 
1859, p. 101) j and the fourteen successive parts have since ap- 
