t S°7 ] 
lary ftrudture, not only of fome of the corals 
and corallines, but of the keratophytons, or fea 
feather ; only with this difference, that the tubes 
of the herring-bone coralline are of a fpongy 
elaftic nature, and always remain open ; whereas 
the others, being of a more foft and vifcid na- 
ture, by time, and the heat of the climate, are 
compreffed together, and harden, fome into done, 
and l'ome into horn or wood : But this I may 
explain, perhaps, more clearly hereafter. 
In Plate XVII. you have, at E , the natural fize and 
appearance of the herring-bone coralline ; at F and 
G the root, and one of the upper branches, are mag- 
nified, to fhew the tubes. 
LXV. Obfervations on the late fever e cold 
Weather . By William Arderon, F. R. S. 
and Henry Miles, D . D. F. R . S. 
Part of a Letter frcrn William Arderon, F. R. S . 
to Henry Baker, F. R. S. containing Obferva- 
tions , made at Norwich, on the late fevere cold 
Weather . 
* 
Dear Sir , 
Read Feb. i i/y Have not time to fend you now a dif- 
*754. tindt account of all the obfervations 
I have been making this fevere feafon y but the few 
that follow will, I hope, excufe me to you, for the pre- 
fent. They were taken by thermometers expofed to 
S s s, 2 the 
