Geological Society. ^77 



F.R.S. Sec, and another " On the tertiary deposits of the Cantal, and 

 their relation to the Primary and Volcanic Rocks," by C. Lyell, Esq. 

 For, Sec. G.S. F.R.S. &c., and Roderick Impey Murchison, Esq. Sec. 

 G.S. F.R.S. &c., was begun. 



May 1. — Concluded Reading. A paper " On the tertiary deposits of the 

 Cantal, and their relation to the Primary and Volcanic Rocks," by Charles 

 Lvell, Esq. For. Sec. G.S. F.R.S. &c., and R. I. Murchison, Esq. Sec. 

 G.S. F.R.S. &c. 



The authors have selected this district for description, because, although 

 the adjoining fresh-water formations of the Limagne d'Auvergne and of 

 Puy en Velay have been largely written upon, yet this of the Cantal has 

 scarcely been noticed by any geologists, except in a cursory manner by 

 Mr. Scrope, and formerly by M. Brongniart in his general observations on 

 fresh-water deposits. {Annates du Museum, torn. xv. 1810.) 



A paper by Dr. Buckland was read, stating that he has ascertained that 

 the bony rings of the suckers of cuttle-fish are frequently mixed with the 

 scales of various fish, and the bones of fish, and of small Ichthyosauri in 

 the bezoar-shaped fagces from the lias at Lyme Regis. These rings and 

 scales have passed undigested through the intestines of the Ichthyosauri. 

 Dr. Prout has also found that the black , varieties of these bezoars owe 

 their colour to matter of the same nature with the fossil ink-bags in the 

 lias ; hence it appears that the Ichthyosauri fed largely upon the sepite of . 

 those ancient seas. 



The author has also ascertained, by the assistance of Mr. Miller and 

 Dr. Prout, that the small, black, rounded bodies of various shapes, and 

 having a polished surface, which occur mixed with bones in the lowest strata 

 of the lias on the banks of the Severn, near Bristol, are also of faecal 

 origin : they appear to be coextensive with this bone-bed, and occur at 

 many and distant localities. He has also received from Mr. Miller similar 

 small, black, faecal balls from a calcareous bed, nearly at the bottom of the 

 carboniferous limestone at Bristol ; this bed abounds with teeth of sharks, 

 and bones, and teeth, and spines of other fishes : until they can be referred 

 to their respective animals, the author proposes the name of Nigrum 

 Grae^cum for all these black varieties of fossil faeces. They may have been 

 derived from small reptiles or from fish, and in the case of the lias bone- 

 bed, from the molluscous inhabitants of fossil nautili and ammonites, and 

 belemnites. In a collection at Lyme Regis there is a fossil fish from the 

 lias, which has a ball of Nigrum Grae^cum within its body; for this the 

 author proposes the name of Fchthyo-copros. He also proposes to affix 

 the name of Sauro-copros to the so-called bezoar stones of the lias at 

 Lyme Regis, which are derived from the Ichthyosauri ; and the name of 

 Hyaino-copros to the A'lbum Grae'cum of the fossil hyaena. 



The form and mechanical structure of the balls of Sauro-copros, disposed 

 in spiral folds round a central axis, are so similar to that of the supposed 

 fir-cones or luli in the chalk and chalk marl, that the author has concluded 

 that these so long misnamed luli are also of faecal origin. On examination 

 he finds many of them to contain the scales of fish ; and Dr. Front's 

 analysis proves their substance to be digested bone. The spiral intestines 

 of the modern shark and ray aifbrd an analogy that may explain the origin 

 of this spiral structure ; and the abundance of the teeth of sharks and 

 palates of rays in chalk, renders it possible that the luli may have been 

 derived from these animals. For these the provisional name of Copros 

 iuloldes is proposed. In the collection of Colonel Houlton of Farley 

 Castle, are several specimens of the Copros iuloides from the quarries of 

 Maestricht. 



The author has also recognised two other varieties of these faecal sub- 

 stances, in a collection of fossils brought from the fresh-water formations 

 near Aix in Provence by Messrs. Murchison and Lyell. 

 Vol. II. — No. 9. c c 



