X 



C. D. Walcott — Cambrian Rocks of Pennsylvania. 473 



At a quarry in a field east of the railroad track and 

 near where the roadway turns to the eastward towards 

 Codorus creek, the strike of the limestone is N. 15° "WV 

 (Mag.), and dip 15° S. One of the layers is quite fos- 

 siliferous and gave 6ne specimens of a species of Salte- 

 rella and Kutorgina, heads of small trilobites of the 

 genera Solenopleura and Zacanthoides, and numerous 

 fragments of the head and thoracic segments of a 

 species of Olenellus. 



Further to the westward in an old quarry east of the 

 Northern Central R. R, track, massive layers of lime- 

 stone are shown that have a strike N. 20° W. (Mag.) ; 

 dip 20 S., and contain fragments of the genus Olenellus 

 and Protypus. The next higher exposure in the section 

 is in a large and deep quarry just west of the R. R. 

 track, between one-fourth and one-half mile south of 

 Emigsville. About 60 feet of limestone is exposed. 

 The strike is E. and W. (Mag.), with a dip of 10° to 

 the south. In the lower portion of the quarry there are 

 massive layers of arenaceous limestone, and about ten 

 feet from the summit of the section, alternating bands of 

 earthy and pure limestone in which numerous fossils 

 occur. In the collection obtained I have recognized : 



Plates of Cystids. 



Kutorgina, n. sp. 



Orthisina festinata Billings. 



Olenellus (fragments). 



Protypus senectus Billings. 

 The fragments of Olenellus indicate individuals as large 

 as any kuown. The fossils range through about twenty 

 to twenty-five feet of the limestone. The layers above 

 the fossiliferous band are largely brecciated and form a 

 limestone conglomerate. The estimated thickness of the 

 entire series of limestone is V50 



In the railroad cut the limestone is shown, and, a little 

 to the south of them, cleaved slates the bedding of 

 which strikes east and west (Mag.) and dips 10° south. 

 There is an interval of 20 feet between the limestone 

 and slates covered by debris. The limestone appears to 

 pass beneath the slates, and from the areal distribution 

 of the slates and limestone to the south and southwest 

 it is probable that this upper band of slates has a wide 

 distribution ; its thickness is unknown. 



An area of quartzite, No. 2 of section, is colored on the map 

 two miles N. W. of Emigsville as of the same age as the 

 Hellam quartzite. It is, as we now know, a thinner belt of 

 quartzite resting in the calcareous and sandy shales above the 

 quartzite of the Hellam hills. The next point determined 

 was the actual relation of the Olenellus quartzite at Emigs- 



