464 REMNANTS OF EXTINCT VOLCANOES. 



of controversy and will I think continue to be so, especially by 

 those who were unfortunate enough to hang up their theory on 

 the wrong peg. I will commence with the Western Nare Head 

 situated to the south of Falmouth ; this portion of Cornwall, 

 as well as the eastern, has its Nare Head, Penair Farm, 

 and its Carn, and on the western Penair farm commences the 

 grand range of quartz and quartzites which form a portion 

 of a circle around the celebrated Hornblendic Serpentine and 

 Gabbro region, the Lizard, a name familiar in almost every 

 civilized country. It is accessible from almost every point, 

 and it is visited by hundreds of people from various parts of the 

 world every summer, therefore any statement I make respecting 

 its geological formation must of necessity be a very careful 

 delineation, and less speculative than the reports often given by 

 writers, especially too, as the district has been visited regularly 

 for the last fifty years by the most eminent geologists. 



I purpose reversing the mode of investigation generally 

 adopted by others, and shall begin with the vein or fissure quartz, 

 such as is found scattered through the strata in which the volcanic 

 energy first found vent ; and then treat with the tufa or frag- 

 ments of the various rocks through which the energetic force 

 found its way, and carried all that was removable with it. 



The vein quartz and quartzites are scattered in great 

 profusion over a belt of land averaging about one mile in width, 

 and extending from the mouth of the Helf ord Eiver to a little to 

 the south of Looe Bar ; quartzites appear to be in the minority, 

 and I believe I am the only person who has been fortunate 

 enough to find a recognizable fossil cast in them. For many 

 summers past I have visited the locality, and have from time to 

 time made enquiries of the stone breakers, and also of Mr. 

 Shephard, the surveyor, but without hearing of any other dis- 

 covery of casts of fossils. However, on a very recent visit to 

 Porthalla, in company with Mr. Crowther, I discovered some 

 boulders of quartzite at Fletching's Cove containing some 

 good casts ; not being able to detach any portion of the stone, 

 I succeeded in obtaining a good pencil rubbing of them. 



The cliffs from the Nare point at the mouth of the Helford 

 Eiver to Porthalla, were visited under very favorable circum- 



