THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE V. VOL. I. 



No. VII. — JULY, 1904. 



OS-IO-XnSTJLXj .A.ISTICLES. 



I. — On the Discovery of Silurian Fossils of Ludlow Age 



IN Cornwall. 



By Upfield Green, F.G.S. 



THIS is merely a brief note to record the discovery of fossils of 

 undoubted Silurian age in the " Black Slates with limestone 

 lenticles " which occur on the shore and in the cliff at Fletching's 

 Cove, near Porthalla, and at Porthluney, near Gorran, in Cornwall. 



For many years the most careful search in these beds for fossils 

 has been unsuccessful beyond minute ossicles of crinoids and 

 indeterminable fragments of Orthocerata. I have spent many 

 weeks each year hunting for fossils, often alone, but sometimes in 

 the company of Dr. Barrels, Mr. Teall, Messrs. Vassell, Sherborn, 

 Howard Fox, and others, and beyond finding the well-known 

 Brachiopoda in the quartzites of Gorran and Came, our search has 

 seemed almost in vain. Some four years ago, however, Mr. Sherborn 

 found in the Black Slates of Fletching's Cove an impression, which 

 he identified as a fragment of Serpulites longissimus, J. de C. Sow., 

 of Ludlow age. This fragment is now in the Museum of Practical 

 Geology. This Spring, in company with Messrs. E. Dixon, of the 

 Geological Survey, and Mr. G. T. Prior, of the British Museum, 

 I paid my usual visit to Cornwall, and was rewarded by finding 

 at Porthluney in these Black Slates a limestone lenticle which 

 contained Orthocerata in quantity. It was only on the 6th June 

 that I showed this to Mr. Sherborn, who at once took it to Mr. G. C. 

 Crick, who recognised two of the fossils therein contained as com- 

 parable with Actinoceras haccatum, H. Woodw., and Barrandeoceras 

 holtiamom (Blake), together with other fragments also of Upper 

 Silurian age. These two Cephalopods taken together with the 

 Serpulites stamp the rock as of uppermost Silurian, probably Ludlow 

 age. The specimen is in the British Museum (Nat. Hist.). 



I think I may now venture to state that we have at last succeeded 

 in establishing a definite fact in the geology of this part of Cornwall, 

 thus fixing a base-line for the rocks intervening between it and the 



DECADE V. — VOL. I. NO. VII. 19 



