40 PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [Apr. 14, 



rect, 6 belong to, or were derived from, the Middle Tertiaries; 

 for the Cetacea and ZijpTims I have assigned only a doubtful 

 origin. 



It will appear from the above analysis that the London Clay has 

 made the largest contribution of species. The greater portion of 

 these organic remains consist of the teeth of Sharks ; and the indi- 

 vidual specimens from the Older Eocene formation bear a larger 

 proportion to the specimens from any other deposit (even allowing 

 for the greater number of teeth these animals possessed) than do 

 the individual species from that deposit to the individual species 

 from any other ; and I beheve the Red Crag Sea to have been 

 principally bounded by land belonging to the London Clay ; and 

 that these fossils have been introduced into the Eed Crag Sea by 

 the simple operation of coast-action ; their rolled or bouldered con- 

 dition resulting from strong or opposing currents running into, or 

 through, that sea. 



Professor Henslow, as it is well known, in 1843 first brought 

 into notice a material he had discovered in the Red Crag, which 

 was then considered likely, and has since proved, to be a valuable 

 boon to the agriculturist ; and, as this substance contained a large 

 portion of the phosphate of lime, it was in consequence imagined to 

 be of coprolitic origin, and the name of ^' coprolite" has to this day 

 been retained by the diggers and dealers in that article. 



The opinions respecting the nature of this material, and of the 

 source whence it was derived, were for some time in an unsettled 

 state, and Mr. John Brown submitted to an eminent chemist, Mr. 

 Richard Phillips, for analysis, some specimens of indurated clay 

 from the Red Crag as well as from the London Clay. The result of 

 that gentleman's examination was published by Mr. Brown in 

 ' Charlesworth's London Geological Journal' in 1846, showing a 

 very strong resemblance in the component parts of the clay from 

 the two different formations ; and, although the opinion respecting 

 the coprolitic origin of the clay has been generally discarded, it is most 

 probably of animal derivation. There is every reason to believe 

 that this phosphatic clay is foreign to the bed in which it is 

 found, and that it has been derived from some antecedent forma- 

 tion ; and, as the Fishes and Crustacea from the London Clay are 

 found imbedded in this material, or their animal portions replaced 

 by it, there is no doubt that some of the clay has been derived 

 from the Older Tertiaries. As, however, this same " coprolite" is 

 met with in the Coralline Crag, this latter formation has also con- 

 tributed, I beheve, a very large portion*. 



* Since this Paper was read, I have again visited the Crag district, and have 

 obtained from the Coralline Crag, at Kamsholt and Sutton, not only amorphous 

 specimens of this " coprolite," which constitutes the main portion of the com- 

 mercial article, but I have found specimens of a peculiar form and character, 

 precisely resembling those which are found in the Red Crag. I would more 

 especially mention some elongate and pointedly oviform nodules of this clay, 

 possessing a smooth exterior with a regular polygonal fracture. These nodules 

 (larger than pigeons' eggs) were found in the Coralline Crag where the shells 

 indicate a quiescent deposit, or, at least, where there could have been only a 



