A LIST OF 
THE IRISH LIASSIC FOSSILS, 
WITH NOTES ON THE NEW AND CRITICAL SPECIES, 
BY RALPH TATE, ASSOC. LIN. SOC., F.G.S., &c. 
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The only Author, excepting myself, who has enumerated the fossils of the Lias 
of the Province of Ulster— that division of Ireland in which, only, that forma- 
tion is developed — is the late General Portlock. 
The specimens on which he based the list in the “ Survey of Londonderry,” 
pp. 747 — 769 (1843), now form part of the Collection of the Museum of Prac- 
tical Geology, London, and that of the Museum of the Irish Geological Survey, 
Dublin ; these I have carefully examined, and the results arrived at are em- 
bodied in List I, in the left hand column of which are arranged the specific 
names quoted by Portlock, and in the right hand those that I have adopted. 
The sign ! is prefixed to those species, original specimens of which I have 
examined. Those included in brackets are for the present expunged from the 
list of Irish Liassic fossils, because from their known distribution, it is ex- 
tremely probable that these determinations are erroneous ; at any rate their 
identification requires further confirmation. Some species, examples of which 
are not now in the Portlockian Collection, have received new names. These 
are adopted, because there is no doubt that they are the species to which 
Portlock’s descriptions are applicable, and which, moreover, have occurred to 
me in the Liassic strata of the North of Ireland. 
The first column of List I. contains 107 specific names, but by the elimi- 
nation of synonyms, and the rejection of a few doubtful determinations, the 
