INTRODUCTION. 
XVII 
Hebden Bridge, and Mr. Francis Looney of Manchester, in sending 
specimens of many fossils from new localities in the limestone shale 
of the vale of Todmorden. Mr. Cooke forwarded for inspection the 
results of his researches in the vicinity of Hesket and Wigton, and Dr. 
Moore several select specimens for comparison and engraving. 
) 
But my greatest obligation is to Mr. Gilbertson of Preston, a 
naturalist of high acquirements, who has for many years explored with 
exceeding diligence and acumen a region of mountain limestone re- 
markably rich in organic remains. The collection which he has amassed 
from the small district of Bolland is at this moment unrivalled, and 
he has done for me, without solicitation, what is seldom granted to 
the most urgent entreaty ; he has sent me for deliberate examination, 
at convenient intervals, the whole of his magnificent collec- 
tion, accompanied by remarks dictated by long experience and a 
sound judgment. He had proposed to publish an account of his 
discoveries, and especially of the Crinoidea for which no man in 
Europe had equal materials, and had made a great number of careful 
drawings for the purpose ; but all these, as well as the specimens, he 
placed at my disposal — a striking proof of liberal and genuine devotion 
to science. 
An attentive examination of this rich Collection rendered it unneces- 
sary to study minutely the less extensive series preserved in other cabinets. 
The Yorkshire Museum contains a considerable number of fossils from 
the limestone districts, chiefly presented by Mr. Danby, Mr. C. Preston, 
Mr. Kirby, Mr. Smith, Mr. Salmond, Mr. Roundell, the Rev. D. R. 
Currer, Mr. Hamerlon, the Rev. W. V. Harcourt and myself. The 
same Museum contains a fine suite of fossils from the Northumberland 
limestones presented by the Rev. C. V. Harcourt. The Collections 
of the Natural History Society of Newcastle-on-Tyne have also been 
of great service to me. In addition to these advantages my own 
cabinet has furnished a few rare species ; most of the figures of fossils 
are taken from specimens in Mr. Gilbertson’s Collection, because these 
were generally the best that could be found. 
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