STUDIES OF THE MA.CROCHIRES. 



365 



plialauges, and the carpo-metacai'j)al boue 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 stchis, and it will be remembered that in TrocMlus 

 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 the Jihula, 

 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 

 square, 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-birdsj 

 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 of certain Cypseli and Trochili. 



Of the External Form and Pterylography of certain Cypseline 



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 platgcercus, and 



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