36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. // 



with its light body, long, slender limbs, and lizard-like foot structure, 

 we have a reptile which fulfils all essentials for the type of animal that 

 made the tracks designated Dolichopodus tetradactylus ; and in Trc- 

 matops and Cacops, with wide, short bodies ai^d short, heavy limbs, 

 are amphibians of the right proportions to have made trails similar 

 to those called Baropezia eakini and Agostopus matheri. I do not 

 wish to imply that the tracks were made by these animals, but the 

 type of creature to which they may be attributed is quite certainly 

 represented. The evidence for such correlation must not be taken 

 too seriously, since at present there seems no way of definitely link- 

 ing up the two lines of evidence. 



No strictly bipedal animals have yet been found in this fauna, all 

 being quadrupedal, and these vary greatly in size from one of a 

 few inches in length to the largest which may have attained a length 

 of several feet. 



Attention should be called to the fact that probably none of these 

 trails shows the normal walking gait, due to the fact that all were 

 impressed by animals climbing a steep slope in soft sand, and this 

 effort has probably, in all instances, shortened the stride. That all 

 of the trails observed, with one exception, lead in a common direc- 

 tion—that is, up the face of the slope — is difficult of explanation. 

 This applies not only to the level where most of the collection was 

 made but also to all other levels in the Coconino where tracks were 

 seen, both perpendicularly and horizontally. It is also of interest to 

 note that the three series of footprints of Laoporus coloradocnsis 

 from the Lyons sandstone of Colorado show the same characteristic. 



The Ichnite fauna of the Coconino sandstone now consists of the 

 following described genera and species : 



VERTEBRATES 



Dolichopodus tetradactylus, n. gen., n. sp. 



Nanopus merriami, n. sp 



Laoporus schuchcrti Lull 



Laoporus nobeli Lull 



Laoporus coloradocnsis (Henderson) 



Baropezia eakini, n. sp. 



Agostopus matheri, n. gen., n. sp. 



Faleopus regularis, n. gen., n. sp. 



Barypodus palmatus, n. gen , n. sp. 



Allopus? arisonae, n. sp. 



INVERTEBR.\TES 



Paleohelcura tridactyla, n. gen., n. sp. 

 Mcsichnium benjaniini, n. gen., n. sp. 



