80 NEW YORK STATE MUSEUM 



as I have endeavored to describe them above, with the same 

 processes as they are found upon the tarsometatarsal of A s i o 

 wilsonianus and F a 1 c o sparverius, some interesting 

 points become apparent. The arrangement in Asio is much the 

 same as we find it in Circus, there being a single foraminal per- 

 foration, while the pedicle of the inner process in the owl is com- 

 paratively a little deeper from above, downward. In the Sparrow 

 hawk, however, we are met by a very different state of things. 

 Here we find the outer hypotarsial process shrunk up to the merest 

 apology for such a process, while the inner one holds a mid shaft 

 position, becomes a very prominent crest, which is carried down the 

 posterior aspect of the bone for fully two thirds of its length, 

 gradually disappearing in the middle of its lower third. Above, it 

 is pierced on either side of the crest by a foramen, these being 

 placed nearly side by side, with the wall of the crest, just described, 

 between them. 



The proximal end of the first digit of hallux is broad and sub- 

 compressed ; the shaft of the bone is strong and stout, its upper 

 aspect is rounded, while below it is flat and slightly grooved longi- 

 tudinally. The trochlear surface is deeply scooped out in the median 

 line, more especially underneath, an arrangement which allows 

 the ungual phalanx to be thrown well toward the sole of the foot. 

 Thus strongly flexed, this harrier in common with other birds of 

 prey can firmly hold the victims it seizes, and even with ease drive 

 its talons into their very flesh. The ungual phalanx of hallux 

 is a very powerful bone, curved throughout and sharp pointed. 

 When held in the position it has when the bird is standing, we ob- 

 serve the following points for examination at its proximal end, 

 from above downward : first, a single median process, the superior 

 convex surface of which is continuous with the line of the upper 

 border of the claw. This process has on its under side a raised 

 median ridge for articulation with the superior groove of the 

 trochlea of the first phalanx. It is produced in the median line at 

 an open angle over a circular projection below it. Here we find 

 on either side of the ridge a concavity, the whole forming the 

 articular surface for the inferior side of the trochlea of the first 

 phalanx. Projecting- in the median line downward and backward, 

 from beneath the parts just described, another prominent process 

 is seen, for tendinal insertion. First phalanx of hallux measures 

 1.8 centimeters in length; the chord of the claw measuring two 



