MTTLLION ISLAND. 35 



A. joint paper by Mr. Teall and myself, fully describing the 

 manner in which, these cherts occur and their supposed relation 

 to the greenstone, was read to the G-eological Society in London 

 on the 8th February last, and was published in the Quarterly 

 Journal. 



Dr. Hinde, one of the first living authorities on this subject, 

 appended, to the paper, notes on the species disclosed by the 

 microscope, with drawings of their various forms ; enlarged 

 copies of which you see on these walls. 



Let us clearly understand what the term Eadiolarian Chert 

 implies. Messrs. Page and Lapworth* describe flint as the 

 name used for impure nodules of silex, abundantly found in 

 chalk strata, while chert is the name given to the impure silicious 

 nodules and layers found in many other rocks. 



The animal kingdom is divided by these authorities into 9 

 sub-kingdoms. The Vertebrate, with man at their head, are at 

 the top of the scale, whilst the Protozoa (from protos, first ; zoe, 

 life) form the 9th sub-kingdom, and occupy the lowest position. 

 The Protozoa are the most simply organised members of the 

 animal kingdom, the most lowly of our fellow-creatures, without 

 nerves and in most species without stomachs. Amongst the 

 Protozoa is the order Eadiolaria, including marine organisms 

 which, though little more than sacs of jelly-like protoplasm, 

 have the power of secreting beautiful reticulated tests or skeletons 

 of pure silica. As regards their distribution in space they are 

 exclusively marine, and are found in all seas and at all depths. 

 The most famous of the Padiolarian clays and marls is the 

 Polycystine marl of Barbadoes, described by Messrs. Harrison 

 and Jukes Brown, the age of which is miocene. According to 

 Prof Haeckel, the number of species of Eadiolaria, in this 

 "Barbadoes Earth," is not less than 400, and is probably more 

 than 500. He states that very many of the Barbadoes Eadiolaria 

 are to-day extant and unchanged in the Eadiolarian oozef of the 

 deep Pacific ocean. Specimens of these Polycystina are exhibited 

 in the microscopes on the table, and micro-photographs will be 

 shown by lime-light this evening. 



* Introductory Text Book of Geology, 1888, p. 72. 



f Nicholson and Lydekker Manual of Palaeontology, 1889, vol. I, p, 149, 



