Prof. C. Lapworth—Olenellus Fauna in Britain. 485 
were detected by me on the flanks of Caer Caradoc in 1885, but 
they were too imperfect for description. During the summers of 
1887 and 1888, Mr. H. Keeping of Cambridge, who has been col- 
lecting under my direction the characteristic fossils of the Lower 
Paleozoic rock-zones of the district, for the Woodwardian Museum, 
has obtained a sufficiency of fragments to enable us to recognize 
a large and well-marked species of Olenellus. This species possesses 
characters apparently intermediate between the European form 
Olenellus Kjerulfi (Linnarsson) and the undescribed American form 
Olenellus Bréggeri (Walcott, MS.) ; but it is so closely allied to the 
last-named species, that I prefer to await the publication of Walcott’s 
diagnosis of his form before publishing its specific description. I 
have provisionally named it Olenellus Callavei, after Dr. Charles 
Callaway, F.G.S., who was the first to demonstrate the presence of 
fossiliferous Cambrian rocks in this Shropshire district, and to collect 
Cambrian fossils from the special strata under notice. 
This lower Cambrian or Olenellus formation of the Shropshire 
area consists of two main members, viz. the basal Quartzite of 
Lawrence Hill and Caer Caradoc, and an overlying green sandstone, 
the Comley Sandstone (Hollybush Sandstone of Dr. Callaway). 
This formation follows unconformably upon the so-called Uriconian 
rocks of the district, and occurs in many localities, as at Lilleshall, 
the Wrekin, Caer Caradoc, Cardington, etc. In mapping this forma- 
tion through the district I find that its fossils are mainly confined to 
the sandstones and to certain calcareous and phosphatic? beds within 
them. In addition to Olenellus we find in various localities such 
characteristic Lower Cambrian forms as Kutorgina, Mickwitzia ? and 
Acrothele. The strata of this Olenellus zone are succeeded irregularly 
by (usually faulted against) the Shineton shales of Dr. Callaway, 
which have long been known to contain in their highest zones an 
abundant fauna of Lower Tremadoc (Upper Cambrian) age. No 
trace of the intermediate or Paradowides fauna has yet been detected. 
Although this discovery has been well known to my fellow- 
workers among the Lower Paleozoic Rocks of Britain, I have 
refrained from placing it upon record, until my identifications could 
be confirmed by foreign paleontologists familiar with the Olenellus 
fauna abroad. But as the specimens I exhibited at the London 
meeting of the Geological Congress were unhesitatingly referred to 
the typical Olenellus fauna by Mr. Walcott and Dr. Schmidt, there 
is no longer any excuse for withholding its publication. 
The necessary geological and paleontological details will appear 
in due course ; but as these new facts may, it is hoped, lead geologists 
in the meantime to a renewed investigation of the strata and fossils 
of the more ancient formations, it will perhaps be of service to 
point out that the detection of this lowest Cambrian fauna in beds 
superior to the Wrekin Quartzite opens out a fresh series of problems 
in British geology. The presence of Olenellus in these beds appears 
at first sight to fix distinctly the pre-Cambrian age of the so-called 
Uriconian rocks of the Wrekin and their British equivalents, and 
even to render the pre-Cambrian age of the Longmyndian a matter 
