146 FiELD CoLUMBIAN MusEuM—GEoLOoGy, VOL. II. 
MEASUREMENTS. 
mm. 
Length ------ ---- ------ ------ ------ ---- ------ ---- ---- ----=~ 252-5- 5255 224 
Width at proximal end ~_2-- 22-53. = ola ns Und St aoe ie ee 18, 23 
Width of shaft at middle---- —---. -.-22252 22 Tis? 
First phalange of wing finger. Pl. XLIV, Fig. 1. The first phalange, as 
usual, lies upon the side in both wings. As in P¢eranodon, it is the long- 
est bone of the body. Its under margin is concave throughout, the con- 
cavity greater near each end. ‘The proximal expanded extremity has a 
deep articular concavity, extending through an arc of about one-third of 
a circle, with its radius directed at an angle about 45° with the long axis. 
The upper, olecranon-like projection has a marked emargination of the 
border above, between which and the proximal end the convexity is 
greater, with the corresponding deeper concavity of the under border. 
There are two articular facets, separated by a median ridge, which 
fits into the trochlear depression of the metacarpal. ‘The posterior sur- 
face extends throughout the whole length of the arc, while that on the 
anterior side reaches but little more than one half of the distance, and ~ 
its upper part is narrower than is the other surface. ‘The pneumatic 
foramen is on the anterior side, just beyond the end of the articular sur- 
face. The dorsal border of the bone is gently and evenly convex from 
a little beyond the proximal extremity, and the width on the distal three- 
fifths is nearly uniform. The distal extremity of the bone is curved 
downward; the articular surface in life was doubtless a vertical oval. 
, MEASUREMENTS. 
mm. 
Léngth --2- 12-22 2-23-42 --24 35 5+ on, Sa ee al 283 
Greatest width at proximal end..-___-... 1+... -..+.-_1.5 J 
Ghord. of! proximalarticulation_-—- <---2-) 522i 22 oa or ie 17 
Width of shaft, proximal: third.._- ----..-- -2-__. -.- 2)... > 14 
Width of shaft, distal third ---2---: ---._--1_-__... -... 14 
Width distal extremity—_.~ /-----+. ----*--- 2... 2 2 18 
Thickness of shaft at middle as compressed +--. ---..__. 2 mee tay 
The second wing phalange (Pl. XLIV, Fig. 5) lies in position in the 
right wing, but is somewhat displaced in the left. It is much smaller 
and more slender than the first phalange. Its proximal border is nearly 
straight and transverse to the axis of the shaft; it is much broader than the 
shaft. The under border of the bone is gently concave throughout, 
except on the proximal part, where the concavity is deeper. The upper 
border, gently concave at the proximal end, is nearly straight thence to 
near the extremity. The distal extremity is quite like that of the first 
phalange, though smaller. 
