208 
description of the fossils. 
ECHINIDA. 
Cidahis vetusta. Ph. Ravenstonedale ; Whitewell ; Northumberland ; 
Coalbrookdale ; Florence Court. (The spine is rudely muricated.) 
C. glabrispina. Ph. Northumberland. (The spine is smooth.) 
New genus. Bolland ; Ireland. 
REMAINS OF MOLLUSCA cuv. 
In presenting the following catalogue of remains of mollusca, it is 
difficult to avoid recalling to the attention of the reader the state of 
opinion formerly prevailing on the subject of the animal remains in 
the older strata. It is within the limited range of the author’s memory 
that the notion of the existence in the mountain limestone of such 
genera as isocardia, nucula, pecten,— patella, turritella, and buccinum, 
would have been instantly rejected as something highly improbable ; few 
persons even at this day are prepared to admit the existence of above 
thirty species of ammonites in the carboniferous sera ; and it will take 
some time to dissipate the false conclusions which have been entertained 
concerning this subject by those who have seldom seen any of the 
fossils except the brachiopoda and cephalopoda. These are indeed 
still the characteristic forms for nearly the whole of the calcareous 
parts of the system, but in several districts, which from various reasons 
are inferred by the author to have been littoral deposits, they are mixed 
with a large proportion of species of other families. I have seen no 
os t real in this series. 
The coa l formation has abundance of unioniform shells : the moun- 
tain limestone and millstone grit almost none of them. Nearly all the 
species known in the whole system are peculiar to it. 
CONCHIFERA PLAGIMYONA. 
Sanguinolaria ? angustata. Ph. PI. V. fig. 2. Bolland 
Transversely depressed, elongated, diagonally carinated, hinge straight 
rows parallel to the margin. 
with fur- 
