vi INTRODUCTION. 
The Third Fasciculus contains the Carboniferous and Permian Mollusca in the 
Cambridge Collection; several of which are so well preserved (especially in the series 
of Carboniferous fossils from Lowick) that the internal characters of the genera could 
be described more accurately than was possible before, on less perfect evidence. 
Among the Palzeozoic Fishes, here described, several new Devonian species have been 
added to the long lists published by Professor Agassiz. So far as regards the Carboniferous 
Fishes, great pains have been taken to ascertain the genera and species which were 
intended by the names given in the Manuscript lists published in the third volume of 
the “Poissons Fossiles:” and the typical specimens have been in all cases consulted in 
the collections of their several owners, so as to enable Professor M’Coy to adopt the 
manuscript names of M. Agassiz, and thereby to give him as much credit for the specific 
determinations as if the several species had been fully described or figured. The figures 
and descriptions of such species in the present work (so far as they are contained in 
the University Collection) will therefore be of some interest; and they are the only parts 
of the Irish Collection, in the Cambridge Museum, which are introduced into this Fasciculus. 
Among the points of interest connected with the Paleozoic Fishes may be mentioned the 
unexpected discovery that the teeth of Cochliodus succeeded each other vertically upwards, 
as in the Pycnodonts; and, consequently, that the near relation which such Fishes were 
supposed to have to the Cestracions could no longer be maintained (infra pp. 621 and 623). 
Before concluding this notice of the contents of the Third Fasciculus, I wish to put 
on record the great obligation the University owes to W. Hopkins, Esq. of St Peter's 
College, for a very fine series of Carboniferous Fossils which were collected by him in 
Derbyshire; and to the Rev. E. Jenkinson, of Lowick, Northumberland, for his noble 
local collection of Carboniferous species, formed by himself during many years of labour. 
Both the above-mentioned collections have now a permanent place in the Woodwardian 
Museum. A like obligation our Museum owes to the generosity of the Rev. W. Stokes, 
of Caius College, and the Rey. J. H. Pollexfen, of Queens’ College. The former gentleman 
has contributed nearly all our best specimens of Fishes, from the Carboniferous limestone 
of Ireland, which are described in the subsequent pages of this Fasciculus: and to the 
latter we owe the best specimens we possess of the Devonian Fishes of the Orkneys and 
the North of Scotland. The Museum is also enriched by a fine series of Palzeozoic fossils 
from various parts of Ireland, presented by Richard Griffith, Esq. of Dublin. Many of 
the species in the Irish Collection had been described by Professor M*Coy in a previous 
work; and none of them (excepting certain Paleeozoic Fishes) are therefore enumerated 
or specially referred to in the following work*. 
illustrations of the following work, I have incurred a great cost. This was well known to the Syndics of the University 
Press, who have generously assisted me by undertaking the cost of the letter-press; but on the positive condition (arising 
out of existing regulations) that my name should appear on the title-page of the work. i 
* Tt is not my duty to enumerate, in this place, any benefactors except those who have contributed to the Paleozoic 
Fossils of the Cambridge Museum. The chief benefactors to the other portions of the Museum are, however, enumerated 
in the “Blue Book” of the “ Cambridge University Commission,” published in 1852 (Evidence appended to the Report, p. 118). 
