No. 387.] REVIEWS OF RECENT LITERATURE. 263 
Obviously Bonasa, with its partly naked tarsus, a very unusual thing 
in this group, stands apart from all the other American genera, and 
the fact that it has developed a special feather-tract on each side of 
the neck does not necessarily indicate any close relationship with 
Tympanuchus, much less that it has an origin in common with the 
latter. The general characters of Zagopus do not seem to imply a 
special relationship to Canace, and may only mean the greater lack of 
specialization of both and their comparative nearness to the common 
ancestor of all the grouse. Centrocercus, on the other hand, shows 
a number of extremely specialized characters alongside of the reten- 
tion of generalized ones, and while it may share origin with Pediocetes, 
Oreortyx 
Lophortyx 
Callipepla 
Cyrtonyx 
Colinus 
Ty 1) + Pt +h by h 
North American quail as divulged 
in their pterylographic characters. 
there is no reason for believing that they have descended from Canace, 
which seems more closely allied to Dendragapus and Tympanuchus in 
spite of the specialization of the neck-tracts of the latter. 
It is to be hoped that Dr. Clark may be able to carry his investi- 
gations on fresh material in this field farther, and especially that he 
may succeed in extending it to more forms of the so-called peris- 
teropod Gallinz, the Curassons and Guans, in Central and South 
America. He may then be able to point to more definite and trench- 
ant characters between them and the alecteropods, in which connec- 
tion I would call attention to the alleged presence of a “ bastard 
secondary ” in the latter and its absence in the former. The peris- 
teropods are, on the whole, considered to be more generalized, 
but highly specialized pterylographic features are apparent in many 
forms — a feature which should not obscure the general proposition. 
LEONHARD STEJNEGER. 
