VOL. XLVIl.] VHILOSOPHICAL TRANSACTIONS. 167 



the sea; somewhat raisal in some places, in others more depressed and 

 flatted. 



There are observed in several parts of the said bark, small tubercles or promi- 

 nencies, (fig. 7, s) which maybe seen even without a microscope. These tu- 

 bercles are pretty large at their bottom or basis, and round (fig. 1, n, n), grow 

 somewhat narrower towards their upper part (o), and terminate in a lip of some 

 thickness, regularly divided into 8 parts (fig. 1, s, s, fig. 8, s, s) more or less 

 even; which form the mouth (fig. 1, t, fig. 8, t, fig. Q, a) of each tubercle, or, 

 to speak more properly, of each cellule. The bark of the coral ends at the ex- 

 tremity of these parts : and thus it is, that all the inner part of each cellule of 

 the white pellicle is formed. The white pellicle (fig. 2, g, fig. 5, n, n) is doubled 

 in some places, and forms a little bag (fig. 6, s, c) which lines the inside of each 

 cellule (t), that is, to the beginning of the lip, or to about the middle of the 

 cellule. 



The substance of the coral (fig. 6, o) gives way to the cellule by small cavities : 

 yet these are not very visible in the old thick branches, but they are pretty easily 

 seen in the young and slender (fig. 4, a, c). Thus the cellule does not end at the 

 coralline substance ; since the white pellicle (fig. 6, s) is between it and the said 

 substance. The hollow of the cellule grows narrow into a sort of cone, with an 

 obtuse apex ; the belly of which is greater in diameter than the basis. The 

 bottom of such a cellule faces the foot of the coral, and its mouth the branchy 

 or most distant part from the foot. In this cellule is lodged the polypus, which 

 is visible to the naked eye, (fig. 7j s) but its exact shape is only to be seen by 

 the microscope ; and it was by this means, that a drawing has been made of it. 



TherefcJre it is from each cellule (fig. 6, t, c) that a white, soft, and some- 

 what transparent polypus (fig. 10) comes forth, or extends itself; which in shape 

 resembles a star with 8 equal rays, nearly conical, (fig. 11) and furnished with 

 other conical appendices (fig. 11, a, a, fig. 10, a, a,) which issue out of it on 

 both sides. The two rows of these have their direction nearly on the same plane. 

 The rays are somewhat flatted, (fig. 10, a, a,) and a trough (fig. 12, c, fig. 10, 

 n, o,) rises out of their centre, somewhat widened at its beginning, with an 

 opening or great mouth at top (n). In its sides there are 8 upright ridges, broad 

 and elevated, and as many wrinkles, or fiirrows ; and each ray is inserted be- 

 tween every two wrinkles (a, a). This trough is placed on a smooth part, (fig. 

 12, g) which we may call the belly of the animal; and this part, while the animal 

 lives, and has not been hurt, is always erect in the cellule ; though it be entirely 

 disengaged, and separated on all sides from the said cellule ; as may be plainly 

 seen in some positions of the polypus. 



All these particularities are to be seen only when J;he coral is just drawn out, 

 of the sea, and suffered to stand in some of the sea-water : for, if you take the 



