41 
on the Ornithology of Guatemala. 
tiore, maculis similibus minoribus variegato : frontis plumis 
et. mystacibus elongatis albis : lateribus capitis pallido rufo 
striatis: subtus intensius ferruginea, ventre medio cinna- 
momescentiore : rostri nigri mandibula inferiore ad basin 
flavicante : pedibus pallidis : long. tota7*5, alse 3*4, caudze 
3*0, rostri a rictu 1*2. 
Coban, one ex. There are examples of a Malacoptila in 
the collection of the Academy of Natural Sciences of Phila¬ 
delphia, U. S. A., which, according to my notes, agree with this 
bird. They are marked as from Vera Paz. The nearest ally of 
the present species is Lafresnaye^s Malacoptila panamensis , from 
which it may be distinguished by the absence of any flammula- 
tions below. It is also not generally unlike M. mysticalis of 
New Grenada, but is easily distinguished from it by its rufous 
tail.—P. L. S. 
Pam. TIlOGONIDiE. 
67. Trogon mexicanus , Sw. sp. 215. 
Volcan de Fuego. The colour of the eyelid of this species, 
both in the male and female, almost exactly corresponds with 
the red colour of the breast in each, that of the male being much 
more brilliant than that of the female, in fact bearing the same 
ratio to it as the colour of its breast to that of the female^s breast. 
It is probable that in many cases the colour of the soft parts 
about the eye, &c., may be determined by reference to some 
portion or portions of the plumage where it is exactly repre¬ 
sented. In the Trogons this seems eminently the case. A few 
days ago I shot a pair of Trogon caligatus , in which the colour 
of the eyelid of the male was exactly represented by the colour 
of the yellow breast; that of the female by the fainter yellow 
of its breast. The same is the case with T. puella . I think, 
therefore, that with tolerable safety the eyelids of these American 
Trogons may be said to correspond with the colour of the breast. 
It certainly is true in all cases which I have noticed. As regards 
the theory itself, though of course there must be many excep¬ 
tions, I may here state that the colour of bare skin round the 
eye of Aulacorhamphus prasinus is exactly repeated in the under¬ 
tail coverts, that of Ramphastos carinatus in the throat, the blue 
being repeated in the colour of the legs. This practice of re- 
