64 Natural Hiftory 



turc, and the whole Subftance of it, feels as light as 



Cork. 



The outward Surface is compofed of a mealy friable Mat- 

 ter of the Colour of red Lead, not unlike the Covering of 

 the common red Coral, as it is brought to us, when firft 

 taken out of the Sea, but fuller of little ftarry Holes. The 

 Matter that compofes the Cells which lies immediately under 

 this, has fome Degree of Tenacity, and the internal Part is 

 ftill more compact, and conlifts of a faint red fpongy Sub- 

 fiance. 



The Surface of the principal Stems are furrounded by pa- 

 rallel Tubes : Thefe Tubes we may trace up along the 

 Branches, till they change infenlibly into Rows of Cells, as 

 we may obferve in fome of the celliferous Corallines. 



Fig, P, Plate XXVI. is a Reprefentation of a fmall Piece 

 of this fpongy Keratophyton, in its natural Proportion. 



Fig. ^ is a Piece of the Top of one of the Branches, cut 

 perpendicularly through the Middle, to {hew the Situation 

 of the Cells. Thefe Rows of Cells furround the young 

 Branches on all Sides ; and the fpongy Parts between them 

 appear in the Microfcope to be full of irregular tubular Ca- 

 viiies. 



The internal fpongy Part of this Species is more intimately 

 united to the cellular cortical Part, than in any other Species 

 we have yet feen. 



Fig. i?, is the horizontal Sedion of the fame Branch, to 

 fhevv the Difpofition ot the feveral Rows of Cells, furround- 

 ing the fpongy central Part. 



I have obferved, in fome Specimens of the pennated Kera- 

 tophylon^ or Sea-Feather, that, when the Whole, or Part of 



it, 



