206 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 24, 



Leptsena sericea ; plentiful Trenton. 



deltoidea ; very abundant „ 



alternata „ 



Orthis (testudinaria) striatula „ 



lynx „ 



pectinella „ 



bellarugosa? „ 



disparilis „ 



Echino-encrinites anatiformis ; plentiful „ 



Glyptocrinus decadactylus „ 



Calymene senaria „ 



Isotelus gigas „ 



Atrypa plena Cbazy. 



Encrinurus, with punctured cheeks. 



Raphistoma, two undescribed species, found also at Poquettes 



Rapid, Allumettes Island. 

 Atrypa, allied to A. extans. 

 or Rhynconella, allied to A. navicula, but with a sinus in 



the front of the larger valve. 

 Fenestella, Lingula, Bellerophon, Orthoceras. 



The fifth new locaHty in which the foot-prints occur is on the 

 Riviere du Nord, in the Seignory of Argenteuil, along which river the 

 sandstone again crops out, and runs in a W.S.W. direction almost in 

 a line with the Valley of the Ottawa (see Map, Sect 3 i and fig. 3) . The 



Fig. 3. — Section across the Riviere du Nord in the Seignory of Argenteuil. 

 Section No. 3 on the Map. 



Distance about 5 miles. 



Gneiss, interstratified with limestone and traversed by dykes of trap and granite. 

 Potsdam Sandstone with the Track-bed. c. Calciferous Sand-rock. 



dip of the strata is here a little more decided than we have yet had it, 

 the inclination heing south at an angle of ahout 4° ; and in the space 

 of a mile and a quarter the stratigraphical relations of the rocks 

 can be well made out. We have first the gneiss and its interstrati- 

 fied limestone ; then the sandstone, not seen in actual contact with 

 it, but forming an escarpment of between 30 and 40 feet in height, 

 between which and the gneiss there is a flat sandy valley, varying in 

 breadth from one quarter to half a mile, in which the stream winds 

 its course. The sandstone has been traced thirteen miles consecu- 

 tively to the eastward, and is known far beyond ; and where a trans- 

 verse section was measured the track-bed occurs at the top of the 

 escarpment at a height of probably 100 or 200 feet over the gneiss. 

 South of the outcrop of the track-bed, about 330 yards over a flat 



