THE 



GEOLOGICAL MAGAZINE 



NEW SERIES. DECADE III. VOL. VII!. 



No. XII.— DECEMBER, 1891. 



oiaia-iisTj^ij .A.I^TIcXlES. 



I. — On Olenellus Gallavei and its Geological Kelationships. 



By Prof. Charles Lapworth, F.R.S. 



(PLATES XIV. AND XV.) 



IN the year 1888 I published a short paper in the pages of the 

 Geological Magazine^ and in "Nature,"^ in which I gave 

 a brief account of the discovery of the fauna of the Olenellus (or 

 Lower Cambrian) zone in the Comley or Hollybush Sandstone of 

 Shropshire. Since that date great advances have been made in our 

 knowledge of the Olenellus fauna of other areas, and the Olenellus 

 zone has now generally attained an established rank and systematic 

 position in the Geological Eecord as the basal zone of the Cambrian 

 system. 



At the time my paper was written sufficient material had been 

 obtained to enable me to recognize the existence of a well-marked 

 species (01. Gallavei) of the genus Olenellus in the Comley Sand- 

 stone series. But the form appeared to be so closely allied to the 

 Olenellus Broggeri, which had been discovered by Mr. Walcott, — 

 the distinguished palaeontologist of the United States Geological 

 Survey — in the basement beds of the Cambrian of Newfoundland, 

 and exhibited and named by him at the meeting of the Geological 

 Congress in London in 1888, that, as I explained in the paper 

 referred to, I felt that it was but just that I should await the 

 appearance of the formal description of his species before publishing 

 my own. 



Thanks to the kindness of Mr. Walcott, his brilliant and long- 

 expected Monograph " On the Fauna of the Olenellus Zone " ^ now 

 lies before me, in which Olenellus Broggeri is admii'ably figured 

 and described; and although it includes a comparative diagnosis of 

 Olenellus Gallavei, sufficient for registration and identification, I take 

 this my first possible opportunity of figuring and describing in full 

 our Shropshire form, that the want of acquaintance with its minor 

 specific characters may not delay those who may be desirous of 

 publishing new species from the Olenellus zone elsewhere. 



1 Lapworth, " On the Discovery of the Olenellus Fauna in the Lower Camhrian 

 Eocks of Britain," Grological Magazine, 1888, Dec. III. Vol. V. p. 485. 

 ^ " Nature," vol. xxix. p. 213. 

 3 See next page. 



DECADE III. VOL. VIII. — NO. XII. 34 



