260 GEOLOGY OF OLD HAMPSHIEE COUNTY, MASS. 



Third. A well-defined Palteoneilo, with coarse surface striae (I obscured the im- 

 pression somewhat by taking a squeeze from it). There are species throughout the 

 Middle and lower Upper Devouian of a similar character. 



Fourth. Well-defined Camarotoechias, like Bhynchonella sappho and R. congre- 

 gata, too obscure for specific identification. 



Fifth. A recognizable fragment of a large Actinopteria. 



Sixth. The "tricircled encrinite" of Eaton and Vanuxem. Though only a crinoid 

 column, this is, 1 think, the safest horizon-marker visible; at least its association with 

 the other fossils mentioned helps to a close approximation to the age of the fauna. 

 Its stout calcareous body has often preserved it from the distortions which have 

 wrecked the associated fossils, and its characteristic expression as it occurs in the 

 lower Chemung and Ithaca beds is well reproduced here. 



Thus I believe we are justified in assuming this fauna from the shaly quartzites 

 to be of Upper Devonian age ; no change from the old conclusion, but a better fortified 

 opinion. 



DESCEIPTIOK OF THE REGION. 



The terrace sauds of the Connecticut River are narrow upon its western 

 side, where the river crosses the State line, and they^ontinue with httle 

 increase of width for 4 miles southwesterly, and then, as they enter Ber- 

 nardston, their boundary upon the older rocks turns abiniptly west and runs 

 for 7 miles a little south of west, past the \allage of Bernardston and along 

 the north line of Greenfield. (See PI. IV.) Bernardston village stands 

 just in the middle of this line and at the mouth of a nan'ow valley, up 

 which a lobe of the alluvial sands reaches northwardly for nearly 2 miles. 

 On the west this valley is bounded by the high ridge of West Mountain, 

 made up of the contorted argillite, which stretches in a nan-ow band far 

 north across Vermont and disappears below the river sands on the north 

 line of Grreenfield, appearing again only in the limited outcrop just west of 

 the village of Wliately, 15 miles farther south, and in one newly discovered 

 at the mouth of Mill River. Everywhere the slope of West Mountain 

 shows only the black argillite, except in a single band back of the house of 

 Mr. F. Williams, a mile north of the village, where, apparently resting upon 

 the argillite, occurs the fossiliferous series. The section has a width going 

 up the hillside on the line of dip of only 3,445 feet. The outcrops of the 

 argillite to the north and south show that there can be only a very limited 

 amount of the newer series preserved upon the hillside, while the heavy 

 accumulation of till generally prevents one's seeing its limits or its contact 



