//. S. Williams — Devonian System of Devonshire, 31 



A kt. IV. — The Devonian System of North and South 

 Devonshire; by II 8, Williams. 



[Read at Toronto. Aug, 30, 1889, before Section K. American Association for 



Advancement of Science] 



Last fall I had the pleasure of examining the typical sec- 

 tions of Devonian rocks in Devonshire, England. I went over 

 the southern sections at Torquay. Saltern Cove and Newton 

 Abbot and neighborhood under the guidance of Mr. Ussher of 

 the Geological Survey, who lias recently made careful study of 

 the localities for the survey ma]), and in North Devonshire I 

 had the guidance of Mr. T. M. Hall, a local geologist at Pilton, 

 who has an admirable collection of the fossils and is personally 

 familiar with the ground. I went across the section from 

 Barnstaple to Ilfracombe collecting fossils myself at the fossil- 

 if- rous zones of Ilfracombe, Sloly and Pilton, Toporchard, 

 Strand and Barnstaple. In Pilton, also, I saw the admirable 

 collection of Mr. Hall In Londor. I examined the collections 

 in the Jermyn Street and South Kensington Museums, at the 

 mer place Mr. Newton kindly showing me survey material 

 not yet reported upon, and at South Kensington Mr. Etheridge 

 showing me his original maps and pointing out the peculiarities 

 of the sections. I also had opportunity, through, the kindness 

 of Mr. Whidborne, of examining the collection of fossils from 

 the limestone of Lummaton. This collection, which was re- 

 ported upon by Mr. Davidson in his Monograph on the British 

 Devonian fossils is, perhaps, the hnest collection in England of 

 the fossils of that zone. In this study of the English Devo- 

 nian that which impressed me most vividly was, 1st, that the 

 fossils are very closely allied to the species in the New York 

 Devonian, although in the great majority of cases passing 

 under different names, and, 2d, that the rocks in their appear- 

 ance, composition and order are as different as two distinct sys- 

 tems well can be. Not only do they differ from those of New 

 York, but the South Devonshire section is utterly unlike that 

 of North Devonshire, quite as unlike as the Old Red sandstone 

 farther north is from either. 



In North Devonshire, the whole series, from the Foreland 

 grits and Lynton slates up to the Pilton beds, is made up of 

 siliceous slates, grits and occasional argillaceous slates, and here 

 and there intercalated beds of impure limestone. The colors 

 are grays and purples with light browns and yellows for the 

 grits. Slaty structure prevails throughout and obliterates or 

 makes difficult of detection the true bedding of the rocks. 

 Fossils are rare except in the limestone layers of the middle 

 part and in the slates and shales of the upper part. The rocks 



