Vol. 54.] FAUNA OF THE SKIDDAW SLATES. 465 



GeoL Soc. vol. i, p. 399. In this paper the author described 

 briefly the range and extent of the Skiddaw Slates as then 

 recognized, and gave some account of their lithological 

 characters. He stated that they contain no organic remains ; 



1848. but he subsequently (1848) called attention to the discovery 

 of two graptolites, and a few so-called fucoids (Quart. Journ. 

 Geol. Soc. vol. iv, p. 223). He concluded that these are the 

 earliest forms of life, and regarded the Skiddaw Slates as 

 representing beds below the Lingula-Fldigs of Wales. 



1863. The first detailed account of these rocks was given by 

 Harkness in his paper on ^ The Skiddaw Slate Series ' (Quart. 

 Journ. Geol. Soc. vol. xix, pp. 113-135). There he described 

 fully the various districts in which the Skiddaw Slates are 

 exposed, and their variation in lithological character in 

 different localities. He also gave sections illustrating the 

 relationships of these beds to others in the district. In 

 conclusion, he referred the Skiddaw Slates to the Lower 

 Llandeilo, that is, to the rocks which, in the Shelve area, 

 overlie the Tremadoc and underlie the main mass of the 

 Llandeilo ( = Arenig in modern nomenclature). 



1876. The next paper of importance is the Geological Survey 

 Memoir on the Northern Part of the English Lake District, 

 written by J. Clifton Ward. He gave a general account of 

 the different rocks to which the term Skiddaw Slates has 

 been applied, and the alteration that these have undergone 

 from various causes. Below the Volcanic Series the sequence 

 given by him is as follows (op. cit. p. 47) : — 



Interbedded volcanic strata and Skiddaw Slates. 

 (5) Black slates of Skiddaw. 

 (4) Gritty beds of Gateso;arth (Buttermere), Latterbarrow, Tongue 



Beck (Skiddaw), Watch Hill, and Grreat Oockup. 

 (3) Dark slates. 



(2) Sandstone series of Grasmoor and Wlaiceside. 

 (l) Dark slates, Kirk Stile, between Loweswater and Crummock. 



He regarded (5) as Upper Arenig, (4) as Middle Arenig, 

 (3) as Tremadoc, and (2) and (1) as the equivalents of the 

 Lingula-Flsigs. 

 1879. This opinion Clifton Ward subsequently emphasized in a paper 

 in Geol. Mag. 1879, pp. 49 & 110, where (on p. 124) he 

 summed up the evidence as follows : — ' The physical evidence 

 inclines one to believe that the Skiddaw Slates include the 

 Arenig Slates, the Arenig Grit, the Tremadoc Slates, and 

 the Lingula-Flsigs.' His conclusions were based entirely on 

 physical evidence, and, in accordance with the custom of 

 that time, the palaeontological evidence was absolutely 

 neglected ; nevertheless, subsequent palaeontological work 

 bears out his views in general, though the actual divisions 

 made by him do not now hold good. 



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