124 report — 1859. 



in the neighbourhood of Birkenhead, and at Lly sfaen near Abergele, and a few other 

 localities. In all these instances the author had observed two pairs of polished 

 surfaces, sometimes within a half-inch, sometimes two feet from another, the 

 intermediate space being occupied by rock more or less altered. These surfaces 

 always exhibit strice more or less inclined. The author concluded by proposing 

 several questions with respect to the phenomenon, with a view to obtain light on it. 



On a Fragment of Pottery found in Superficial Deposits in Paris. 

 By M. A. Radiguel. 



On the Origin of" Cone-in-Cone" By H. C. Sorby, F.R.S. fyc. 



Cone-in-Cone is met with in so many stratified rocks, that most geologists must 

 be familiar with its general characters, 'though no one appears to have thoroughly 

 investigated it, or to have given any very satisfactory explanation of its origin. 

 The cones often occur in bands parallel to the stratification of the rock, their apices 

 starting from a well-defined plane ; and, after extending upwards or downwards 

 for a greater or less distance, with their axes perpendicular to the plane of the 

 stratification, they end in bases parallel to it, but not all at the same exact level, 

 some standing up above the general surface. They are not perfect cones, but are 

 of such forms as would result from the varied interference of surrounding cones, 

 and from the development of others within their own substance. On examining 

 thin, transparent sections with a low magnifying power, under polarized light, the 

 author had been able to ascertain that this peculiar structure is intimately connected 

 with some kinds of oolitic grains. In the formation of the most abundant variety 

 of oolitic grains small prismatic crystals of more or less pure carbonate of lime 

 were deposited round a nucleus in nearly the same amount on all sides, so as to 

 give rise to irregular ovoid bodies ; whereas, in the formation of cone-in-cone, very 

 similar crystals were deposited almost entirely on one side, along the line of the 

 axis of the cones, in such a fan-shaped manner as to give rise to their conical shape. 

 In the thin sections of some specimens every connecting link between imperfect 

 oolitic grains and genuine cones can be seen to great advantage with polarized 

 lio-ht. The growth of the cones did not however proceed without interruption, for 

 other smaller fan-shaped groups were developed within the larger; and thus by 

 the mutual interference of contiguous groups and of others contained within them- 

 selves, there was formed a mass of irregular cones enclosing other cones. The 

 author therefore concludes that this structure is one of the peculiar forms of con- 

 cretions, formed after the deposition of the rock in which they occur, by the 

 crystallization of the carbonate of lime and other isomorphous bases. 



On some Fishes and Tracks from the Passage Rochs and from the Old Red 

 Sandstone of Herefordshire. By the Rev. W. S. Symonds, M.A., F.G.S. 



I have little to add to the Table of Sir Roderick Murchison, published in the 

 Quarterly Journal of the Geological Society, giving a synoptical view of the Old 

 Red Sandstone of Britain and the Devonian rocks of Devonshire and the continent ; 

 with the list of fossil fishes of the Old Red ichthyolites of England, Scotland and 

 Russia. The fishes of the Upper Ludlow rock can no longer be denominated as the 

 first of their class, for that most ancient known fish, the Pteraspis Ludensis, has been 

 detected both in the Lower as well as the Upper Ludlow rock. 



It has been said that "Life is governed by new conditions, and new conditions 

 imply new races ;" and I suspect that when more of the leaves of the massive volume 

 of historic geology are cut and deciphered, it will be found that whole tribes and 

 races of animals have been extinguished by geologists before they were extinguished 

 by Nature, while many were called into existence, and flourished for ages, though 

 as yet they have not been disinterred from their mausoleum of rock. 



The Pteraspis Ludensis is known in the Lower Ludlow rock of Murchison, and 

 has been found in the Upper Ludlow deposits below the bone-bed ; while Pteraspis 

 Banksii, which occurs in the passage beds that link the Upper Silurians with the 

 Lower Old Red, appears to connect the passage rocks with the zone of the Old Red 

 charged with abundant remains of P. Lloydii, P. rostratus, and Cephalaspis Lyellii,. 



