24 



Old Red Sandstone. This led him to some concluding re- 

 marks on the succession of life, traceable, as far as we know 

 at present, — for on this he laid great stress, remarking that 

 any such generatizatiuns are simply provisional, and may 

 be upset by a single adverse fact if brought to light in the 

 process of research— in the Silurian and earlier systems. 

 First a lowly organized foraminifer— a mere speck 

 of Sarcode, not flesh, in a calcarous sheath, 

 the Eozoon Canadense of the North American Laurentians ; 

 then the zoophyte of the lower Cambrians, the Oldhamia, 

 together with a few scanty traces of worm tracks ; then in 

 the " zone primord iale," a larger number of creatures, re- 

 presenting s parsely the three lower sub-kingdoms ; then in 

 the lower and upper Silurians, an abundant supply of re- 

 presentatives of these lower sub-kingdoms, Radiata, Mol- 

 lusca, and Articulata ; and, lastly, at the very close of the 

 Silurian epoch appear vestiges of the lowest member of the 

 Vertebrate sub-kingdom, fish. 



At the close of this very interesting lecture, a vote of 

 thanks was accorded to Dr. Mitchinson by the President, 

 who took the opportunity of remarking that the lecturer's 

 kindness in thus coming forward to exhibit the results of 

 his holiday excursions was an example worthy of being fol- 

 lowed by other members of the Society. He concluded by 

 expressing the hope (in which all present joined) that they 

 might before long have the pleasure of hearing from him a 

 further discourse on the same subject. 



Several fossils and specimens were displayed by Dr. 

 Mitchinson, which were minutely examined by the com- 

 pany ; also microscopes by the President and Mr. S. Harvey. 



