﻿GEOLOGY OF LESMAHAGO. 53 



to the complete series of body -rings, including the ' telson ' or terminal segment ; the 

 body-rings themselves lifting out from the matrix and presenting both the dorsal and the 

 ventral aspect. The thoracic plate is also seen in situ, the great swimming-feet (or 

 ectognaths) attached to the head, on the centre of which last are seen the larval eye-spots 

 (ocelli), and the great compound marginal eyes, with their facets as beautifully preserved 

 as if it were a living Crustacean and not a remnant of a Palaeozoic age. The friable 

 condition of the fossil alone has prevented the possibility of obtaining the loan of it for 

 delineation, but I hope to be able before the completion of this present Monograph to 

 offer to the Society a fitting representation of this truly wonderful Pterygotus, 



8 



