LETTER XXVII. 



ATTEMPT TO ASCERTAIN THE NUMBER OP SPECIES OF THESE 



ANIMALS. 



IT is my intention to devote the present letter to the endeavour to as- 

 certain, as nearly as I may be able, the real number of species, under 

 which such of these extraordinary animals, whose remains we are at pre- 

 sent 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 de- 

 scribed in Letter XVII. of the present volume. 



II. The CAP ENCRINITE of Derbyshire, and perhaps of York- 



shire ; see Letter XIX. 



Ill 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. 



