?>2 



SMITHSONIAN MISCELLANEUUS COLLECTIONS 



VOL. 80 



The stride as compared with the width of trackway would seem to 

 indicate an animal with considerahle length of leg, and it is incon- 

 ceivable that the imprints are other than those made by feet on 

 separate legs, a conclusion substantiated by the direction of the claws 

 or toes. While the tracks give the impression that all four were 



Fig. 13. — Ocfopodicliinis didaclyliis. Type. No. 1 1,501, U. S. N. M. 

 Diagram of trackway. About j natural size. 



moved forward simultaneously, it may be that one leg was moved 

 forward at a time after the manner of progression of many existing 

 invertebrates. 



GENUS TRIAVESTIGIA, new genus 



Generic characters. — A continuous trail of three parallel sets of 

 markings, between two of which there is a faintly impressed tail 



