78 THE CAMBRIAN. [nuu.81. 



granite is eruptive through, and therefore newer than the Primordial 

 slate. The evidence of the trilobites shows that the slates were formed 

 very far back in geological time, and near the base of the recognized 

 geological formations. In a resume of the geological history of the 

 Boston Basin, 1 a general description of the Primordial slates and quartz 

 ites and their physical relations is given. 

 In mentioning the discovery of fossils in the limestones at Nahant, Mr. 



A. F. Foerste correlated the Nahant limestone with the red slates of 

 North Weymouth, and concluded that they are strati graphically beneath 

 the Braintree Paradoxides beds, and that the red slates of Mill Gove at 

 North Weymouth are of Olenellus age and beneath the Paradoxides 

 strata. 2 



In 1889 Mr. A. C. Lane described the geology of Nahant from a miner- 

 alogical standpoint, 3 and in the following year Prof. J. H. Sears pub- 

 lished a description of the stratified rocks of Essex County, which in- 

 cludes the limestones and associated slates of Nahant. He mentious 

 finding Hyolithes princeps, Hyolithes communis var. emmonsi, Hyolithes im- 

 par, and Stenotheca rugosa.* He also discovered an outcrop of the Lower 

 Cambrian limestone in a valley between Prospect Hill and Hunslow's 

 Hill, in Bowley, in which fragments of Hyolithes occur. 



PALEONTOLOGY. 

 NEWFOUNDLAND. 



The first announcement of the discovery of the Cambrian fauna in 

 Newfoundland appears to be by Mr. J. W. Salter 5 in the description of 

 Paradoxides bennettii. He referred the species to the " Lingula flags or 

 Zone Primordiale." 



From collections made by the Canadian Geological Survey Mr. E. 

 Billings described in 18G1 6 the fauna from the Cambrian strata on the 

 north side of the Straits of Belle Isle, on the Labrador shore, at L'Anse 

 au Loup, and assigned it to the horizon of the " Lower Potsdam," corre- 

 lating it with the fauna found in Franklin County, Vermont, which is 

 described in the same paper. The species described are Palwophycus 

 incipiens, Archwocyatlms atlanticus, Obolus labradoricus, Obolella chro- 

 matica, 0. (Kutorgina) cingulata, Conocephalites miser, Bathyurus senectus, 



B. parvultiSy Salterella rtigosa, S. pulchella, and S. obtusa. The uew 



'Op. cit.,pp. 19-22. 



2 The Paleontological horizon of the limestone at Nahant, Massachusetts. Boston Soc. Nat. Hist. 

 Proc, vol. 24, 1889, pp. 261-263. 



3 Geology of Nahant. Boston Soc. Nat. Hist. Proc:, vol. 24, 1889, pp. 91-95. 



4 The stratified rocks of Essex County. Essex Institute Bull., vol. 22, 1890, p. 32. 



6 On tbe fossils of the Lingula flags or "Zone Primordiale." Quar. Jour. Geol. Soc, London, vot 

 15, 1859, p. 552. 



6 Paleozoic Eossils, vol. 1. Containing descriptions and figures of new or little known species of 

 organic remains from the Silurian rocks. 18ti0-1865. Montreal, 18G">, pp.426. (Of this volume pp. 

 1-24 were issued in November, 1861 ; pp. 25-5G issued January, 1862 ; pp. 57-168 issued June, 1862; pp. 

 169-314 issued February, 1865 ; pp. 395-416 published in Canadian Naturalist, vol. 5, 1860, pp. 301-324.) 



