128 Reviews — M. Barrois — Chalk of the Isle of Wight. 



Billings, it possesses a skeleton consisting of two walls or floors, 

 each made up of rhombic plates, fitting in one to another ; separating 

 and supporting the two floors or decks are a great number of thickish, 

 calcareous, vascular columns, which are traversed by an internal 

 canal with ramifications in each of the floors. After illustrating 

 this structure, Giimbel points out that the calcareous skeleton, there- 

 fore, possesses an anastomosing canal-system ; and hence the columns 

 are not analogues of Sponge-spicules, nor is the whole structure 

 equivalent to the embryonal form of Sponges, as regarded by Billings ; 

 but, on the contrary, corresponds closely with Foraminifera, among 

 which it forms a genus, not of the Orhitolitidm, as suggested by 

 Salter, but strictly near the Dactyloporidcd, as an allied family — that 

 of the BeceptacididcB. These conclusions are clearly illustrated by 

 numerous accurate drawings from Dr. Giimbel's microscopic sections 

 of Beceptacidites. 



The bibliography and history of opinion as to the nature of this 

 fossil creature are fully given by Dr. Giimbel. The localities and 

 range are also indicated. IscJiadites and Tetragonis have not yet 

 been submitted to close study ; but the author is of opinion that, 

 though closely allied to BeceptacuUtes, they have specific, if not sub- 

 generic, differences. A synonymic list of the known fossil forms 

 coming under these names is given at pages 38-40 ; and other 

 probably allied forms are also enumerated. T. K. J. 



le, IB -V I E -VsT S . 



♦ 



Description Geologique de la Ceaie de l'Ile de Wight. Par 

 M. Charles Barrois, Preparateur de Geologic a la Faculte 

 des Sciences de Lille. 



HAEDLY any spot in the United Kingdom is so attractive to ail 

 classes of people as the Isle of Wight. To the geologist, 

 however, this island is of peculiar interest, owing to the number of 

 formations there represented, and the admirable cliff sections and 

 fruitful fossiliferous localities around its coast. Hence it has been 

 the subject of numerous papers and memoirs. But room has still 

 been left for further research, of which M. Barrois has availed 

 himself, and in the present paper he has given the result of his 

 observations. 



After reviewing the literature on the subject, the author proceeds 

 to give a topographical sketch of the position of the Chalk, which 

 is divided by an anticlinal line running east and west along the 

 island into two portions, dipping in opposite directions. 



The southern mass rests on the Upper Greensand, and consists of 

 Chloritic Marl (zone of Am. laticlavius) . overlain by the Chalk Marl 

 (zone of ScapJiites ajqualis). This latter is a com2)act, greyish-blue 

 chalk, with conchoidal fracture, containing numerous nodules of iron 

 pyrites, about 115 feet thick. The general dip is from 5 to 10 

 degrees to the south. 



The flints in this district, though apparently intact, fall to pieces 



