1887] Geology and Paleontology. 367 
_ more or less rounded, still fitting into their original places, al- 
though bat decayed connecting rocky matter has long since 
been removed. Most of the boulders have spheroidal or ellip- 
soidal rare and resemble as much northern erratics, or perched 
blocks, as any seen within the drift zone of America or modern 
glacier regions of Europe. One of these boulders is about 
thirty feet long, fifteen feet broad, and twenty feet high, perched 
on top of a rounded hummock, and resting on only a few small 
ints. 
AW ea one compares the forms of these rocks south of the 
line of northern drift, and of others similar in the more southern 
rounded surfaces of Norway, still in contact with living glaciers, 
—where he may see how unimportant a factor is the land-ice in 
gnawing away the old crystalline rocks,—one is forced to look 
upon the structure of both as more or less of common origin,— 
atmospheric erosion, perhaps aided by iP „although the 
latter region has been swept off by a brush of ice which has 
left scratches behind—F W. Spencer, ppm of Missouri, 
Columbia, Mo. 
e Dinosaurian Genus Colurus.—This genus was de- 
scribed by Marsh, in 1871, from material obtained in the Ju- 
rassic deposit of Wyoming Territory. Characteristic bones not 
distinguishable as to genus from those described by Marsh are 
in my collection from New Mexico, probably from beds of Tri- 
assic age. They consist of nearly all parts of the skeleton, ex- 
cepting jaws and teeth, and but little of the skull is determinable. 
The material is much more complete than that described by 
Marsh. 
The remains show that the genus Coelurus is a Dinosaurian, 
and I cannot agree with Professor Marsh’s view “that Cœ lu- 
rus cannot be placed in any known order.”? The ilium has the 
xio: io 
Ceelurus is in fact allied to Megadactylus (Hitchcock) from the 
Trias of Massachusetts, differing principally, so far as determina- 
ble, in the form of the condyles of the femur. They are simple 
in Coelurus, but in Megadactylus the external condyle has the 
double character seen in Megalosaurus.3 
The —— are all of slender proportions, especially those 
of the neck and tail. These, with most of vets bones of the 
z Amer. Journ: Arts, : eX. 
3 S Cone T = Reps a S Soc., xiv., 1870, Plate eh 
