STUDIES OE THE MACROCHIRES. 
365 
phalanges, and the carpometacarpal bone is much of the same 
shape as we find it in Passeres generally. 
To one point I desire to direct special attention, and that is — 
that in all Swallows in their carpo-metacarpal bone the meta- 
carpal which belongs to the index digit is considerably shorter 
than the one which belongs to the annularis digit of this com- 
pound bone. This arrangement is strikingly apparent in such a 
bird as Progne suits, and it will be remembered that in Trochilus 
this is also the case, though not so marked ; whereas in Swifts 
the reverse condition obtains, and the metacarpal of the index 
digit is rather the longer of the two. 
Little need be said here in regard to the osteology of the 
pelvic limb of the Swallows, for from femur to phalanges it is 
characteristically Passerine, and in every species the relative 
lengths of the several long bones composing it are harmoniously 
proportioned. Be it noted, however, that Swallows always 
possess a 'patella, and that in them the pro- and ectocnemial 
processes of the tibia are always well developed, while th q fibula, 
although often of only hair-like proportions {Progne), descends 
below the middle point of the shaft of the tibio-tarsus. 
Further, in the hypotarsial process of the tarso-metatarsus 
there are four perforations for the passage of tendons, these 
openings being arranged as though they were at the angles of a 
squai’e, one pair being next to the head of the bone, and the 
remaining pair immediately behind them. 
When I come to review, further on, the characters of the 
pectoral and pelvic limbs of certain Swifts and Humming-birds? 
it will be necessary to revert again to some of these Hirundine 
characters as found in their limbs ; and so it will not be necessary 
to enter more fully into details at this point, but rather reserve 
them for the more effective work of actual comparison. 
On the Morphology oe certain Cypseli and Trochili. 
Of the External Form ancl Pterylography of certain Gypseline 
and Trochiline birds. 
Very good hints sometimes as to a bird’s affinities may be 
gathered from a study of its general contour and form after 
it has been carefully plucked for the purpose. With this in 
view, and in this way, I prepared specimens of Micropus 
melanoleucus , Chcetura pelagica, and Trochilus platycercus, and 
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