[ n6 ] 
dichotomous branches ; each branch is made up of 
two rows of cells united together, and thefe cells 
placed in fuch a manner fide by lide, that each cell 
joins two others on one fide, and the bottom of one 
is inferted in the top of the other. Their openings 
or faces look one way : they are nearly of an egg- 
fhape, a little comprefs’d before : the broadett part is 
uppermoft, and bends a little forward : the top of each 
is fortified by two angular points or fpines. 
By attentively viewing many fpecimens of this ge- 
nus of corallines in the microfcope, that have been 
taken out of the fea at different feafons of the year, I 
have obferved the progrefs of nature to be pretty 
nearly thus : 
The tubuli, or firft beginning of the corallines in 
the younger fate, are found full of a yellow foft fub- 
ttance, which foon decays : in the more perfeCt ftate 
they are clear and tranfparent. 
The cells, which communicate with thefe tubes,, 
have in the fpring black fpecks in each, which I take 
to be the embryo of the future production. During 
this very tender and minute ttate, the opening of each 
cell is cover’d with an extreme fine tranfparent mem- 
brane, the ufe of which no doubt is to cherifh and pro- 
tect it. 
Thefe fpecks in time fwelling into fpherical tefta- 
ceous bodies (as they are often found in fummer) 
burtt through this membrane, and fit in the front of 
the cell, fupported by an umbilical ligament, which 
is fatten'd to the bottom of the infide of each cell or 
matrix, till they come to maturity, which feems to- 
be the cafe in the microfcopical drawing I have fent 
you : wherein you will obferve, they appear to be rows 
of very final 1 fea fnails, or rather tettaceous bodies. 
