
1126 The American Naturalist. [December, 
thus, as in the European Pterodactyls, corroborating the evidence that 
the fifth toe is the one that is rudimentary. All these phalanges are 
slender, excepting the second ones in the third and fourth toes, where 
they are scarcely longer than wide. 
From evidence obtained in the field and i in the laboratory, I think I 
can safely say the following in general of the American Cretaceous 
Pterodactyls, About five or six species are known, varying in size, 
when alive, of from about four feet to not over twenty feet in expanse of 
wing.! The head (in all the larger species, at least) was elongate and 
slender, with a well-developed occipital crest, and without teeth. The 
jaws may have been encased in horn, but I have never seen any evi- 
dence whatever that such was the case. The neck was moderately 
elongate and slender; the thoracic girdle very stout and rigid, sup- 
ported above, in some species at least, by union with the codssified © 
thoracic vertebrz, below by the stout anterior projection of the large, 
rounded, thin sternum. The arms and wrists were very powerful; the 
second, third, and fourth fingers, as Marsh has shown, small and short, 
but terminating in strong, recurved claws ; the fifth, or extraordinarily 
developed wing-finger, having very great freedom of backward move- 
ment at the extremity of the elongate metacarpal, and with only lim- 
ited motion between the four phalanges. The body was short, the 
pelvis of moderate size, the hind legs comparatively small, with great 
freedom of movement, the tail short, and the feet without much, if 
any, prehensile power. Their food probably consisted of fishes.® . 
All the bones throughout the skeleton are very thin-walled and 
pneumatic. The’ haversian canals and lacune are small.—S. 
WILLISTON. : 
Geological News. 
of mineral resin resembling amber along the ridge of a beach on the 
west shore of Cedar Lake, North Saskatchewan, Canada. It has evi- 
dently been washed up on shore by the waves, but its exact age has 
not been determined. (Am. Journ. Sci., October, 1891.) 

Archean.—Mr. J. W. Gregory is convinced that the Tudor speci- 
men of Eozoon is not of organic but of mineral origin. (Quart. Journ. 
Geol. Soc., August, 1891.) 
* This expanse has often been given much greater than this, but I have actually meas- 
ured the largest species (P. umérosus Cope), and know that the size cannot exceed that 
given above. 
5 Several coprolites found within the above-described pelvis, ellisoidal in shape, and 
about the size of an almon = Ee bones so finely comminuted that their precise char- 
acter could not be made 


