238 
THE GEOLOGIST 
prosecuting a study which would from its comphcation have lost all 
those charms which Nature lays open to the studious miud. 
A con'ect section of the British Carboniferous System, with a list 
of the species peculiar to each zone or stage, as well as of those which 
possess a greater vertical range, is, as we have already stated, a gi-eat 
desideratum, and is a subject well worthy of the attention of the 
geologist and paleontologist. Such an investigation is being carried 
out by Doctors White and Oppal, Prof Suess, Mr. Eugene Deslong- 
champs, and others Avith reference to the Jurassic strata ; and the 
others systems have been likewise to a greater or lesser extent 
similarly investigated ; but the Carboniferous one (which is so far 
spread and so important) appears to have been in reality less com- 
pletely and carefully studied with respect to the distribution of its 
species than almost any other ; although we possess many valuable 
works by several of our most eminent geologists and palaeontologists 
in which the system and fossils have been minutely described. Two 
great helps wliich recent species atford are almost entirely precluded 
from the palaeontologist, that is to say, the power of being able to 
anatomically examine the animal, and the absence of that coloration 
which is often of so much assistance in the discrimination of recent 
shells ; and when we reflect how vivid, beautiful, and varied must 
have been the tints which once adoi'ned the now black and dingy 
fossil, we ai'e delighted when, by some fortunate accident, some re- 
mains of that colour is faintly preserved upon a shell which has, for 
almost countless ages been concealed from the sight of man. The 
interiors and well preserved internal casts should likewise be care- 
fully collected, for upon them are impressed many signs which can be 
intei'preted by the experienced palaeontologist, and lead him to re- 
construct and describe many characters in an animal of which no 
living representatives may at present exist. 
In the first pages of this paper, we endeavoured to give some brief 
and general idea of the principal divisions into which the Carbon- 
iferous system had been divided, as well as some details regarding 
that of Scotland in particular. Since then, Mr. Geikie, of the 
Geological Survey of Scotland, has kindly transmitted to me the 
annexed tabular view of the Carboniferous series of the Lothians, and 
which appears to be nearly the same as in the western districts. In 
the Lothians, the Brachiopoda range only in that portion of the 
system, or section, which corresponds to the Carboniferous Hmestone 
of England, some species ranging from the top to the bottom of this 
division, but the greater number appear confined to the lower lime- 
stone series. lAngula mytiloides is stated by Mr. Geikie to be in the 
Lothians characteristic of a zone about the middle of the Edge Coal 
series ; but more information may be expected as soon as the Survey 
shall have published the results of their careful and assiduous labours. 
Mr. George Tate, whose knowledge of the Carboniferous system is 
well known, has, at my request, favoured me also with a note upon 
his "Tweedian group," which we will here transcribe, as it will explain 
the views of that excellent observer, as developed relative to some of 
the oldest beds of the system in Berwickshire and Northumberland. 
