C. D. Walcott — The Taconic System of Emmons. 235 



that only the Scolithus had been found in situ. Professor JEL 

 M. Seely had traced the Rockville " Lingula " to a bowlder, 

 taken from a stone wall, and also the reported Lake Dun more 

 specimens to bowlders on Sunset Hill : no fossils being found 

 in situ. In company with Professor Seely, I visited the Lake 

 Dunmore locality, and found fossils in rounded quartz bowlders, 

 but the quartz ledges gave no traces of them. The Woodford 

 locality was too indefinitely described to be found ; but as trans- 

 ported bowlders afforded me Notkozoe and traces of trilobitic 

 remains, similar bowlders were probably the source of the speci- 

 mens mentioned. In Sunderland, east of Arlington, on Roaring 

 Branch, Scolithus occurs abundantly in situ, in the quartzite; 

 and angular blocks of quartzite were found, one mile up the 

 ravine, that contained Hyolithes and fragments of trilobites ; 

 but they were not traced to the beds from which they were de- 

 rived. Two miles east of Bennington, however, success attended 

 my search for fossils in situ. The section begins in the woods 

 on the west slope of the mountain on the old Weeks farm north 

 of the old Windham turnpike. 



Wooded slope, above pasture. ...- 75 feet. 



1. — Light-gray, nearly white, compact, fine-grained 

 massive-bedded quartzite, with alternating 

 beds of hyaline quartz. Dip 0° to 5° S. E. ; 

 strike, N. 35° E. (magnetic) 35 " 



2. — Light-colored, bedded quartzite, with brown 

 spots ; showing grains of sand and fossils : 

 the latter also in the compact rock. 

 Fossils : Nothozoe, Hyolithes and Olenellus* 40 " 



3. — Alternating bands of layers of light-gray and 

 hyaline quartzite, becoming more massive 



near the summit _. 325 " 



The clip increases from 5° to 10,° 15° and up to 

 25° S. E., on the line of the section, and a lit- 

 tle farther south, to 45° S. E. Strike, N. 45° 



E. (magnetic) 



400 feet. 



The quartzite was traced north into the valley of Roaring 

 Branch, and it is a continuation of the deposit on the western 

 slope of Bald Mountain ; to the south it extends along the west 

 side of the ridge leading to Dome Mountain, in Pownal, north- 

 east of Williamstown, Mass. It caps the latter and crosses the 

 narrow valley on the south to the Clarksburg group of moun- 

 tains, along the slopes of which it extends to a point opposite 

 Williamstown, where it bends eastward along the south face of 



* I have shown elsewhere that the genus Olenellus is characteristic of the Middle 

 Cambrian horizon, over wide areas in North America, and that it is a pre-Potsdam 

 type. (Bull. TJ. S. Geol Survey, No. 30, 188H.) 



