Ixxvi PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 1 895, 



eastern America ; (3) in the region drained by the Baltic Sea. Up 

 to 1888 no recorded account of the discovery of Olenellus from the 

 British Isles had been published, the oldest fauna described being 

 the overlying Paradoxides-zones or Middle Cambrian formation. 



The first recognizable traces of Olenellus in Britain were discovered 

 by Prof. Lapworth in 1885. Further collections were made in 1887 

 and 1888, on the flanks of Caer Caradoc, Shropshire, and the species 

 was named, in honour of Dr. Charles Callaway, Olenellus Callavei. 

 Later on it was figured and described in the Geological Magazine 

 for 1891. 1 



In August, 1891, Sir A. Geikie announced, at the British Association 

 Meeting in Cardiff, the discovery of Olenellus by Messrs. Peach and 

 Home, in blue-black shales, a few feet below the ' Serpulite Grit ' of 

 the Cambrian rocks of North-west Scotland, in the Dundonnell Forest 

 district of Boss-shire. The description of ' the Olenellus-zone of the 

 North-west Highlands ' formed the subject of a most valuable paper by 

 Messrs. Peach and Home, read before the Geological Society on the 

 10th February, 1892, and a new species of Olenellus is described 

 and named 0. La/pworthi by these authors. 2 Mr. B. N. Peach, F.B.S., 

 communicated a second paper, 'Additions to the Fauna of the 

 Olenellus-zone of the North-west Highlands,' on the 20th June, 

 1894; in which, in addition to 0. Lapworihi, he describes and 

 figures 0. Laynvortlii var. elongatus, 0. reticulatus, 0. gigas, 0. inter- 

 medins, and Olenelloides armatus. 3 



' The Fauna of the Lower Cambrian or Olenellus-zone ' forms the 

 subject and title of an admirable monograph by Mr. C. D. Walcott, 

 F.G.S., 4 which, with the exception of the subsequent discovery of 

 an Olenellus-faMna. in the Lower Cambrian of the Scotch Highlands 

 (already referred to), gives us a very complete and up-to-date 

 account of this interesting and oldest fauna. 



About 18 widely distributed localities are shown on the map of 

 North America from British Columbia to Labrador, and as far south 

 as Texas ; whilst in Europe fwe have Spain, N. and S. "Wales, the 

 Scottish Highlands, Norway, Sweden, Finland, Bohemia, Bavaria, 

 Podolia, Sardinia, Petchoraland, and the Ural Mountains. 



Omitting' trails, burrows, and tracks, the Olenellus-fauna. has 

 yielded 55 genera of organisms, 15 of which are trilobites. 



1 Geol. Mag. 1891, p. 529, pis. xiv. & xv. 



2 See Quart. Journ. Geol. Soc. vol. xlviii. (1892) pp. 227-242, pi. v. 



3 Ibid. vol. 1. (1894) pp. 661-676, pis. xxix.-xxxii. 



4 Quarto, Washington, 1890, issued in 1891, pp. 264, with six engraved maps, 

 50 plates of fossils, and 26 illustrations in the text. 



