452 
Mr. C. Lapworth on the Geological 
Dr. Hicks in 1874* * * § , and separated for the first time into sub¬ 
ordinate groups upon the combined physical and palaeontolo¬ 
gical evidences. Their included Graptolites were subsequently 
made the subject of a supplementary memoirf by Mr. Hop- 
kinson and myself. Here, for the first time, do we find proofs 
of the Arenig age of the more typical Skiddaw Slate of the 
north of England ; the distinctness of the Llandeilo grapto- 
litic fauna as compared with that of the true Arenig is ren¬ 
dered tolerably clear; and some progress is made in fixing the 
peculiar species of its subdivisions. 
The Graptolite-bearing rocks of Conway, Tremadoc, Shelve, 
Meadowtown, Ludlow, Builtli, &c. have been partially ex¬ 
amined either by Mr. Hopkinson or myself; but our know¬ 
ledge of the range of the Graptolithina in Wales is still 
miserably defective. 
Ireland .—The rich Graptolite fauna of the Lower Paleo¬ 
zoic rocks of County Down has been most carefully worked 
out by Mr. William Swanston, F.G.S., and illustrated with 
great care and completeness;};. 
Extra-British Rocks .—The new facts brought to light in 
Thuringia, Brittany, New York, and the Western Territories 
will be referred to in their proper place, when the distribution 
of the extra-British species falls to be discussed. 
By far the more important of our new data in this respect 
are owing to the industry of the Scandinavian paleontologists. 
As early as 1874 Dr. Tornquist § marked the presence of 
many British Graptolites of the Coniston type in the rocks of 
Dalarne, but, relying upon the documents published up to 
that date, erroneously paralleled their containing beds with 
the English Caradoc. M. G. Linnarsson has recently made 
the vertical distribution of the Graptolites in the Swedish 
rocks the object of a persevering and most successful study, 
lie has already enriched the literature of the subject with 
several important memoirs ||; and the material he has collected 
goes far to demonstrate the general identity in range of the 
forms common to Britain and Scandinavia. 
No exhaustive summary of these recent discoveries has 
hitherto appeared; but several palaeontologists have given 
distinct indications of an appreciation of the value of these 
new data and of the results to which they converge. 
* Quart. Journ. Cteol. Soc. vol. xxxi. p. 167. 
t Quart. Journ. Geol. Soc. vol. xxxi. p. 631. 
t Proceedings Belfast Nat. Field Club, Appendix, 1876-77. 
§ CEfversigt af K. Vetenskaps-Ak. Fdrliandlingar, Stockholm, 1874, 
no. 4, p. 26. 
|| Geol. Mag. 1876, p. 241 ; ibid. 1878, p. 278, &c &c. 
