300 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



DESCRIPTION OF PLATE 47 



PAGE 



Protichnites septemnotatus Owen. (See pi. 46) 278 



Figs. I and 2. (Natural size.) Right and left side of broad track 13-15 

 cm., showing the trifid tracks. The central portion of the 

 track has been cut out in order to bring the imprints of the 

 two sides within the limits of the plate. U. S. National 

 Museum, Catalogue No. 58593. 

 The specimen represented is from locality (220b), Upper Cam- 

 brian, Potsdam sandstone, near Beauharnois, Province of Quebec, 

 Canada. 



