326 Bulletin American Museum of Natural History. [Vol. XXIV, 



is flat, rather narrow and long, slightly broadest at base, the average width 

 being rather more than one-half the length. The coracoid is undeveloped. 

 The point of greatest contraction of the blade is just below the acromion 

 process ; from this point it abruptly expands to form the broad, deeply hol- 

 lowed glenoid fossa. The blade is slightly concavo-convex, the surface 

 smooth. The following are the principal measurements : Greatest length, 

 1011 mm.; extreme breadth, 830 mm.; length of suprascapular border, 

 following the curvature, 1270 mm.; circumference just below the acromion 

 process, 710; transverse breadth of glenoid fossa, 240; antero-posterior 

 breadth of same, 310; length of acromion process, 200; greatest breadth of 

 same (at base), 130; thickness of suprascapula border, 60-75 mm. (Plate 

 XXIV, Fig. A.) 



The scapula varies in size and somewhat in form in different individuals, 

 and even in the same animal, as shown by the following table. 



mm. mm. 



Height, 1020 breadth, 1250 Iceland (Guldberg). 



1080 " 1220 



965 1200 right! 



953 " 1143 left j Amaganset (Andrews) 



" 830 " 1011 Provincetown (Allen). 



Pectoral Limb. The bones of the right pectoral limb (Plate XXIV, Fig. 

 B) were still (when studied) held in place by cartilage, except the 5th digit, 

 the phalanges of which, however, were still ligamentously connected. Only 

 the terminal phalanx of the 3d and 4th digits were wanting. The distal 

 epiphysis of ulna and radius are ununited, while the proximal are firmly 

 ankylosed, as are both epiphyses of the humerus. The humerus is a short, 

 thick bone, deeply constricted around the middle, expanding distally for 

 articulation with the bones of the forearm, and becoming greatly enlarged 

 at the proximal end. The following are its principal measurements: 



mm. 



Extreme length 520 



Greatest transverse diameter proximally 375 



of head 325 



distally 300 



Antero-posterior diameter of head 300 



Least circumference of shaft at middle 600 



The radius is broad and flat distally, the transverse breadth of the distal 

 border equalling seven tenths of the total length of the shaft; proximally 

 it is much less expanded and much thicker. The point of least breadth is 

 at one fourth the whole length from the proximal end. The following are 

 the principal measurements: 



