Eiirypterid Remains in Carhoniferous Shales of Scotland. 499 



257. Herbert Spencer. The Fiictors of Organic Evolution. 



Nineteenth Century, No. 86, 18S6. Kosmos, xvii. 

 Separately— Williams & Norgate, 1886. Cf. The 

 Leader y 1852 ; Principles of Biology, 1859. 



258. Geoffroy St Hilaire. Principes de Philosophic zoologiqne. 



Paris, 1830. 



259. Treviranus, Gt. R. Biologic, oder Philosophic der lebenden 



Natur, Pt. i. Gottingen, 1802. Erschcinungen luid 

 Gesetze des Organischen Lebens, 1831. 

 Interprets ahiiost all in terms of environmental influence. 



260. Wallace, A. B. Contributions to the Theory of Natural 



Selection, 1871, etc. The Origin of Species and Genera. 



Nineteenth Century, vii., 1880. 



261. Weismann, a. Studies in the Theory of Descent. Mel- 



dola's Trans., 1880-1882. 



XXXIX. On the Prevalence of Eiirypterid Remains in the 

 Carloniferons Shales of Scotland. By James Bennie, 

 Esq., of the Geological Survey of Scotland. 



(Read 21st March 1888.) 



In this paper it is intended to put upon record some facts 

 about the Eurypterids which I have become acquainted with 

 in my researches for spores among the coals and shales of 

 the Carboniferous formation. These facts seem to me to 

 prove that individuals of that family were not rare, as the 

 few instances of their occurrence on record suggest, but 

 extremely abundant^certainly as to individuals, and pro- 

 bably much varied as to species— during the whole of the 

 Carboniferous period. The extreme paucity of the record as 

 to individuals and species is well shown in a paper by Dr 

 Woodward in the Geological Magazine for November last, 

 wherein he enumerates five species, represented by seven 

 specimens, which he says is complete for the Devonian and 

 Carboniferous formations. To Dr Woodward's list must be 

 added another species — Eiiryj^tervs Stevensonii — described by 



