NO. 9 NEW YORK POTSDAM-HOYT FAIJNA 279 



grained, smoother surface than those at Beauharnois, and the indi- 

 vidual impressions of the feet are more numerous and crowded along 

 the main lines of tracks. 



Formation and locality. — Cambrian (Upper ?), Potsdam sand- 

 stone: (220b) Rogier's farm just west of Beauharnois, Province of, 

 Quebec, Canada. 



PROTICHNITES LOGANANUS Marsh 

 Plates 48 and 49 



Protichnites loganantis Marsh, 1869, American Journ. Sci., 26. ser., Vol. 

 48, pp. 46-49. (General description, discussion, and illustration.) 



Protichnites logananiis Marsh, 1869, Proc. American Assoc. Adv. Sci., Vol. 

 17. PP- 322-324. (Same as preceding reference, except that the plate is 

 omitted; also the footnote regarding Doctor Dawson's view.) 



The tracks are described as having been made by a smaller animal 

 than the one that made the Beauharnois Protichnites tracks ; also 

 that there was no medial trail or tail mark as in the latter tracks. 



I collected from near the type locality several slabs of the sand- 

 stone with many tracks on them. Some of these have a median trail 

 or furrow that indicates two terminal spines on the pygidium, or, 

 which I think is the more correct view, the furrow with deep sides 

 was formed by the dragging of the anterior portion of the caudal 

 furca of the trilobite on the sand. That some series of tracks are 

 without the median trail indicates that the animal that made the 

 tracks kept well up from the sand, while others that may have been 

 heavier or weaker touched and dragged some portion of the median 

 dorsal surface or the caudal furca along on the sand. 



Formation and locality. — Upper Cambrian, Potsdam sandstone: 

 (77) Sandstone near the water below the falls at the high bridge, and 

 also at several horizons in the canyon, the highest point being 70-75 

 feet (21-22 m.) above the water, in Ausable Chasm, Essex County, 

 New York. 



