O. C. Marsli— American Pterodactyls. 343 
powerful wings in flight, the pectoral arch is strengthened, (1), 
by the anchylosis of several vertebra : (2) by the “robust scap- 
ule articulating on opposite sides of the common neural spine 
of these vertebre.* ‘This is virtually a repetition of the pelvic 
rch, on a much larger scale. ne genus of American 
iNataieoss ee (Nyctodactylus) was apparently with 
out this > e.t 
In same geological horizon with the gigantic form 
Preranodon beds), the remains of a single small Fiala! 
have been found. This animal was more diminutive than the 
Jurassic aie, having a spread of wings not more than three 
or four feet. The jaws were proportionally more rile than 
in the larger Cretaceous species, and no teeth have been found 
with them. The humerus had a small head, and an pets 28 
wee humerus see ey ea eet ee te eee 
Greatest diameter of he ad, sei elec Maer te ere 12 
Transverse diameter across radial Orem, G5. 30 
Greatest diameter of distal e nd, eee «| 
Vertical diameter of humeral glenoid cavity, eee 3 
Transverse diamet GOP, Se a oid ee wae ees 6 
This species may be called Pteranodon nanus. Its known 
remains were found by Mr. S. W. Williston, in the Middle 
Cretaceous of Western Kansas. 
Yale College, New Haven, Conn., March 21st, 1881. 
* This peculiar wire spine with its o sot 2 articular facets seems to be 
Present also in som of tho Khaliah Cretaceous Pterodactyls. hehe figured and 
described it as a «frontal ~ ° (ty rise Sty 1351, Sup. I, p. 12, Plate IV, figs. 
ley re; 
e name Nyctosau urus, applied by the writer to this group, Fo Sapte to have 
preocen pied, and ioe note a be replaced by Nyctodactylus. only species 
Known is Nyctoductyl 
