202 ; : ; t ' MEMOIRS OF THE CARNEGIE MUSEUM 



; ; for'anjen J- The inner one of these is large, and not only communicates with 

 ine interior of the shaft but passes also directly through it appearing to the inner 

 side of the base of the hypotarsus as a large foramen. Two or three much smaller 

 foramina appear upon the opposite side of the hypotarsus, and they lead to similar 

 passages through the shaft. 



A prominent feature of this bone is its large hypotarsal process. This is com- 

 posed of a thick, oblong piece or internal portion, which is capped upon its posterior 

 aspect by an elliptical, vertical cap, having slightly protruding margins. 



Two very much smaller such plates are developed external to this larger one, 

 having each only about one half its altitude, and being not more than one fourth as 

 thick. By their posterior surfaces more or less ossifying across, two vertical tubes 

 are formed, an internal and external one, through which the tendons pass in life. 

 As thus formed, this hypotarsus stands out rather abruptly and perpendicularly 

 from the shaft, with hardly any inclination to merge with it at its lower part, as is 

 the case in a good many birds. As to the shaft of this bone, it is convex posteriorly 

 and strongly marked by the raised muscular lines ; it is concaved slightly in front, 

 the excavation being very deep proximally ; shallow in the middle third ; and deep- 

 ening a little again as it passes into the usual foramen between and above the external 

 and middle trochlear processes. These latter are large and normally disposed, the 

 mid one being the lower of the three, while the internal and external project about 

 equally backwards. The facet for the free first metatarsal is concave and of some 

 considerable size. The os metatarsale accessorium is a little over two centimeters long, 

 presenting the usual head and being slightly twisted upon itself distad. It agrees 

 with the toe-joints in being non-pneumatic. These latter are nearly all straight, 

 only some of the distal ones being slightly curved. For a bird as large as a Pelican 

 they indicate rather a feeble foot, and this is further sustained when we come to see 

 the weak terminal joints, which are ti'ansversely somewhat compressed, not very 

 long, but withal distinctly, in fact rather strongly curved. These phalangeal joints 

 are arranged upon the plan of 2, 3, 4, and 5 bones to the hallux, second, third and 

 fourth toes respectively. 



Pelecanus fuscas has a femur 8.5 cm. long; a tibio-tarsus of 12.5 cm.; a tarso- 

 metatarsus of 7.8 cm. and a mid-anterior basal phalanx of pes of about 3.9 cm. in 

 length. 



When one comes to think of it then, a Pelican has rather a peculiarly balanced 

 skeleton. Its lower jaw is considerably longer than its ulna, and the latter is in turn 

 considerably longer than the humerus. This last-named bone is only a little more 

 than half as long as the carpo-metacarpus of manus. The tibio-tarsus and the carpo- 



