ON THE OSTEOLOGY OF NYCTOSAURUS. 145 
MEASUREMENTS OF PTEROID. 
mm, 
Cength =.=. -.- ay A pe BE DS Ne AE REPRE sh lias eh aa EA Dh Le eg Ryle Yee a ar en ie 104 
Seer qciiiat proximal end ys. 20.222. ee 15 
INGE CHC reSUIACe - 4... kL doe So alee dents 8 
.The next three metacarpals are, for the most part, wanting in this 
specimen, a single complete one lying near the distal extremity of the 
right wing metacarpal (Pl. XLII, Fig. 6). It is a very small, splint- 
like and slightly curved, pointed bone, measuring about twenty-four 
millimeters in length by two in greatest width. Its resemblance to the 
corresponding metacarpals of Preranodon is so great that the whole 
structure of the hand is doubtless the same in the two genera. I give 
herewith a diagrammatic figure of these parts in Preranodon, based.on a 



Fic. 2. Metacarpals of Preranodon ingens. 
specimen in which nearly all the bones were present and in position, 
some of the terminal phalanges only being misplaced, and one or two of 
the fourth finger missing. Ina former paper I stated that the phalanges 
of the hand were of two kinds, long and short. Possibly this is the case 
in some of the smaller species, but I think not. I doubt not that the 
small phalanges there described were from the foot, and had become dis- 
placed and associated with the hand phalanges in the specimen described. 
In the specimen of Preranodon the small metacarpals seemed to lie, 
not as they are diagrammatically figured, one above the other, but more 
side by side. The second metacarpal is continued, as already stated by 
Marsh, to the carpus, as a thin, thread-like bone. It was not continued 
along the dorsal side of the bone, but seems to pass to the radial side, 
where it belongs. From this it seems also probable that the position of 
all three bones in life was along the radial dorsal margin of the fifth 
metacarpal. 
Both of the wing metacarpals (Pl. XLIV, Fig: 2) lie upon the dorsal 
surface, a position in which they are seldom found. ‘The bone is much 
broader at the base, tapering to beyond the middle, whence the shaft 
has nearly parallel sides. The proximal articular surface cannot be 
made out, though there appears to be a division into two facets. The 
condyles, as in Preranodon, are placed obliquely, the posterior one the 
larger. 
