Revietcs— Nicholson and Ethericlge — Fossils of Girvan District. 135 



due to the author himself, who has furnished the materials as far 

 as the essential ideas of his book are concerned. The work is 

 one which will certainly become classical. 



Lausanne, 1878. 

 [Translated by E. B. T., from the " Archives des Sciences physiques et naturelles," 

 1878, November number.] 



EEVIE "W S. 



I. — A Monograph of the Silurian Fossils of the Girvan 

 District, in Ayrshire, with Special Reference to those 

 contained in the " Gray Collection." By Professor H. 

 Alleyne Nicholson, M.D., D.Sc, etc., and Robert Ethe- 

 ridge, Jun., F.G.S., etc. Fasciculus I. Rhizopoda, Actinozoa, 

 Trilobita. 8vo. 135 pages and 9 plates. (Blackwood and 

 Sons, Edinburgh and London, 1878.) 



SOON after fossils were first collected and brought to notice in 

 the district referred to, Sir Roderick Murchison devoted a 

 large portion of a Memoir on the Silurian rocks of Scotland (in the 

 Quart. Journ. Geol. Soc. London, vol. xvi. 1851) to the elucidation 

 of the contorted and dislocated strata in which they had been 

 discovered. He writes : " The most fossiliferous Silurian rocks 

 yet discovered in Scotland lie directly to the East of Ailsa Crag, 

 and to the north and south of the port of Girvan. . . . The rocks 

 constituting the Silurian series of Ayrshire consist of (3) schists 

 and limestones, (2) shelly greywackes, sandstone with conglomerates, 

 and (1) limestone and schists," in ascending order. "These ridges 

 are composed of strata which strike from W.S.W. to E.N.E., or 

 parallel to the general direction of the Silurian rocks of the South of 

 Scotland. The Girvan Water and the Stinchar flow in longitudinal 

 depressions or fissures, 1 which are also coincident with the strike of 

 the rocks" (pp. 141-3). Not only the recognition of the Girvan 

 fossils (mostly collected in those days, we believe, by John Carrick 

 Moore and Alexander M'Cullum) as Silurian, but the discovery 

 that the old Silures had inhabited this part of Ayrshire, was a source 

 of great gratification to Murchison ; and he urged the further collec- 

 tion of the organic remains, and induced Mr. J". W. Salter to 

 enumerate and describe those already in hand (op. cit. p. 170, etc.). 

 Sedgwick and M'Coy also had already taken a similar interest 

 in this PalaBozoic locality, and had studied some of its fossils (Rep. 

 Brit. Assoc. 1850, etc.). 



With the progress of the Geological Survey the Silurians of 

 Ayrshire became still better known (Explan. Sheets 7, 13, 14, and 

 15) ; and the importance of having their fossils definitely determined, 

 and fully compared with those of Wales and elsewhere, was so 

 strongly felt that a Government grant of £75 was obtained through 

 the good offices of the Royal Society towards the work ; and Robert 



1 The Geological Surveyors, however, did not find a general concordance of the 

 lines of valleys with faults in this district, though the strike of the beds has certainly 

 an influence on them. See " Explan. of Sheet 7, Mem. Geol. Surv. Scotland, 1869." 



