392 
DR. R. W. SHITFELDt’s MORPHOLOGICAL 
particular, I am inclined to believe that the order Trochili will 
he found to he an unusually well-circumscribed oue, containing 
upwards of 500 species, to represent it. 
Since completing the main part of this paper, and especially 
since closing the list of acknowledgments at its commencement, 
I have received many kind letters relative to the work from 
fellow labourers in the same fields, and in some cases valuable 
material for comparison. 
Chief among these it gives me great pleasure to thank Professor 
W. K. Parker, E.R.S., for many timely hints upon avian rela- 
tionships, and for his ready encouragement of my work during 
the time it has been in progress. I am grateful, too, to Sir 
Edward Newton, C.M.Gf., formerly of the Colonial Office, of 
Kingston, Jamaica, for his efforts to secure me specimens of 
Hemiprogne zonatus ; to Lieut. Edgar A. Mearns, of the 
Medical Corps of the United States Army, for specimens of 
Humming-birds from Arizona ; to Mr. Robert Ridgway for 
having directed that the entire collection of birds in alcohol at 
the Smithsonian Institution should be gone over with the view 
of filling up gaps in my desiderata, although at that time it was 
found that no specimens in alcohol of the Macrochires were in 
the collections of that Institution ; and finally, to Mr. E. Stephens, 
of San Bernardino, California, for the loan of many valuable sterna 
of American Trochili, from his private collections. 
EXPLANATION OE THE PLATES. 
(All the figures in the Plates were drawn by the Author from the specimens.) 
Plate XVII. 
The pterylosis of Ampelis cedrorum. 
Fig. 1. a. Ventral aspect, b. Dorsal aspect. Considerably reduced. 
2. Muscles of the patagium of the right wing in Ampelis cedrorum , seen 
upon the outer aspect, and X 2. tp. I, tensor patagii longus; tp. b , 
tensor patagii brevis ; dt. p, dermo-tensor patagii ; d, deltoid ; t, 
triceps ; b, biceps ; e. m. r. I, extensor metacarpi radialis longus ; h, 
humerus; n, ulna. 
3. Right lateral view of the skull of Tyrannies verticalis, J ; life-size. 
I, the free lacrymal bone. 
4. Same view of the skull of Ampelis cedrorum, <S ; life-size : letters the 
same. 
5. Same view of the skull of Hcsperocichla neevia, ; life-size. 
