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LETTER XXVII. 
ATTEMPT TO ASCERTAIN THE NUMBER OF SPECIES OF THESE 
ANIMALS. 
It is my intention to devote the present letter to the endeavour to 
ascertain, as nearly as I may be able, the real number of species, 
under which such of these extraordinary animals, whose remains we are 
at present acquainted with, may be arranged. With this view, I shall 
place before you a recapitulatory sketch of the several species which 
have been described in these pages, and shall add to these such species 
as have been mentioned by some authors ; but the specimens of which 
are so rare as not to have come under the observation of but very few 
others. 
The several species which have been particularly noticed in this 
volume are, — 
I. The Lily Encrinite, described by Walch as the encrinite with 
a pentagonal base, and ten bifurcated rays; being the Stone-Lily 
of Germany, so accurately examined by Rosinus, and described 
in Letter XVII. of the present volume. 
II. The Cap Encrinite of Derbyshire, and perhaps of Yorkshire ; 
see Letter XIX. 
III. The Turban Encrinite of Shropshire ; see Letter XIX. Some 
very indecisive remarks on some remains of this species, from 
the Isle of Gothland, I have shewn, have been made in Knorr s 
celebrated work. 
