THE 



AMERICAN JOURNAL OF SCIENCE 



[FOURTH SERIES.] 



Abt. XXI. — Fossil Footprints from the Grand Canyon of 

 the Colorado; by Richabd Swank Lull. With Plates 

 I, II, III. 



[Contributions from the Paleontological Laboratory, Peabody Museum, 

 Yale University, New Haven, Connecticut, U. S. A.] 



Material containing the imprints of Paleozoic quadru- 

 peds from the Grand Canyon has come to me from 

 three different sources : from the Wesleyan University 

 Museum through the courtesy of Professor William 

 North Rice, from the United States National Museum, 

 and from Professor Schuchert of Yale. The first con- 

 sists of two small fragments of gray sandstone, each 

 impressed with a single obscure track. They were col- 

 lected by Mr. W. H. Weber, and bear catalogue number 

 3572 of the Wesleyan University collection. The second 

 is a fine slab collected in 1916 by Doctor L. F. Noble at 

 Hermit basin, at the same place discovered the year 

 before by Professor Schuchert, and bears no fewer than 

 ten impressions of manus and pes pertaining to the larger 

 species of Laoporus, n. gen. I am indebted to the United 

 States National Museum for the privilege of studying 

 this specimen. Part of Professor Schuchert 's find con- 

 sists of two slabs of sandstone collected in 1915 at Her- 

 mit basin, on the trail down to Hermit Camp and about 

 150 feet above the base of the Coconino sandstone. 

 These have been tinted red by weathering, although the 

 fractured rock is grayer in color. The assumption is 

 that all of the material is contemporaneous. Of Schu- 

 chert 's material the larger slab contains about thirteen 

 pairs (manus and pes) of impressions, varying in their 



Am. Jour. Sci.— Fourth Series, Vol. XLV, No. 269.— May, 1918. 

 24 



