a te ie i eal fo a 
1876.] Zoölogy. 115 
“Graylock range” as an instance of the southward dispersion of this 
bird in the breeding season, at page 141 of the Birds of the Northwest. 
The proper allusion is to some mountains in North Carolina. — E. C. 
HOMOLOGIES or MAMMALIAN TEETH. — Professor Cope has recently 
investigated the homologies of the different types of mammalian teeth. 
He refers all of them to four types, the haplodont, ptychodont, bunodont, 
and lophodont. The first is a simple cone or truncate cylinder in form, 
and from it all the others are derived by folding vertically (ptychodont) 
cle, and that this is connected with the outer front one of the four by a 
low ledge. Successively the two hinder tubercles disappear, and the 
front or fifth grows larger. The ridge connecting the latter with the 
outer grows longer and higher, and the inner front then disappears. 
Finally the hinder part of the tooth disappears also, leaving but two 
apices connected by a cutting edge, which is characteristic of the flesh- 
tooth of the lion and tiger. 
The human molar tooth is one of the simpler forms of the bunodont 
division, 
Protective RESEMBLANCE IN THE YeELLow-Birp. — On passing 
an embankment of the Grand ‘Trunk Railway at Fort Gratiot, Michigan, 
one warm day in August, 1872, we noticed that numbers of the yellow- 
bird ( Chrysomitris tristis Bon.) had collected where an extensive growth 
of the common mullein ( Verbascum thapsus L.) lined the slope. Each 
bird had perched on the apex of a spike of the blossoms, the color of 
Which was almost the identical shade of yellow in the plumage of the 
ird. The mulleins were ranged in stiff files, like soldiers in yellow uni- 
forms, and each bird, as we passed, remained motionless, looking like a 
continuation of the spike, of which one might be easily deceived into 
thinking it part and parcel. As soon as we had passed by, the birds 
Were again busy, flitting from plant to plant, feeding on the seeds, and 
enjoying themselves. 
