Dr. J. E. Marv—The Ashgillian Series. 67 
specimen now placed among the Caradocian fossils in the Sedgwick 
Museum, on whose authority I cannot say, but Professor Hughes, 
who knows the district well, assures me that at the time of this 
determination ,considerable confusion existed as to the age of the 
various beds there. 
There are various references to the occurrence of Zrinueleus in both 
Lower and Upper Llandovery rocks in the Mem. Geol. Survey, vol. 11 
(3rd edition, 1881), but the information given is of the vaguest, and 
I cannot help suspecting mistakes. 
In 1877 Professor Harkness & Nicholson gave in the Quarterly 
Journal of the Geological Society a list of trilobites from the Stockdale 
Shales. In this was included Zrinucleus fimbriatus, a determination 
which Professor Nicholson subsequently admitted to be founded on 
error, and accordingly the species was not recorded in the later paper 
on those shales by Professor Nicholson and myself. 
On the Continent one example of Zrinucleus Wahlenbergi is recorded 
in Kjerulf’s ‘‘ Veiviser”’ from stage 5 (of Llandovery age). It occurred 
in a nodule, and may possibly be derivative. 
In any case the extreme rarity of the genus in the Valentian rocks 
is in marked contrast to its abundance in even the highest (Slade) 
stage of the Ashgillian Beds, though it must not be supposed that 
Trinueleus is common or even represented in all Ashgillian strata; it 
is, for example, distinctly rare in those of most localities in the North 
of England. 
Of trilobite species which, so far as I know, are confined to Ashgillian 
rocks, I may mention Enerinurus sex-costatus, Chetrurus oclolobatus, 
Cyphoniscus socialis, Remopleurides longicostatus, and Ampyx tumidus. 
There are many others which have hitherto been found in one or two 
localities only. 
Several forms which occur rarely in Caradoc rocks are more abundant 
in the Ashgillian strata, as Acaste Brongniarti, Agnostus tumidus, and 
Phillipsinella parabola. 
The graptolites found at Desertereate will enable us to compare 
those rocks with their graptolite equivalents in the Moffat area. As, 
however, the work is being done by Mr. Fearnsides and his colleagues, 
we must await the publication of their full results. 
The following lists of fossils will be useful to students of the 
Ashgillian rocks at home and abroad :— 
Mem. Geol. Survey, Catalogue of Lower Paleozoic Fossils in the 
Museum of Practical Geology (1878). In this list the specimens 
recorded as from ‘‘ Rhiwlas”’ are, I believe, in all cases from the 
Staurocephalus Limestone. The various papers alluded to above mostly 
have fossil lists. In the paper by myself on ‘‘ The Coniston 
Limestone,” the Keisley species, as above stated, belong to the 
Ashgillian, and not, as there recorded, to the Caradocian. A full 
list of the Keisley fauna is given in Mr. Reed’s papers on the 
Keisley Limestone. The South Welsh forms are recorded in the 
paper by Mr. Roberts and myself, and in that by Mr. Evans. Irish 
forms of Ashgillian age are noticed in Messrs. Gardiner & Reynolds’ 
papers, and in the brief notice of the Pomeroy Beds by Mr. Fearnsides. 
A few Scotch forms are mentioned in Prof. Lapworth’s Girvan paper. 
