C 120 ] 
chanel runs its whole length, and where deepefl is an 
inch and half over, but it gradually grows shallower 
and narrower towards the fmaller end. The tides are 
a quarter of an inch in thicknefs. 
B 2, thews the fame foflil body with the rounded 
part upwards. Its tides from a to b are two inches. 
Great numbers of black fhining tubercles, of the kind 
defcribed Fig. Ay but in general larger, and with lefs 
variation in their fize as to one another, are difpofed 
in rows, pretty regularly in the manner thewn in the 
picture. Many ot them appear flarry or radiated with 
icvcral tine lines from the bafe to the apex, which 
lines rife a little, and in fome portions to the light 
appear of a whitith colour. 
Two feparate figures of thefe tubercles are given 
(/>, q) to make this account the better underftood. 
One is a tide and the other a front view. They ate 
■tfiewn magnified about eight times. 
C y is a fotiil body, much more folid and weighty 
than the former two. Its length is ten inches. It 
is rounded on the upper part, where the fides in the 
broadeft place are one inch three quarters : the under 
part has a hollow or chanel one inch and an eighth in 
depth, feven inches and a half long, one inch and a half 
over, its bottom rounded. From a three inches and a 
half to b is quite folid, and at a in width one inch and 
a quarter, whence it goes tapering to by where it is 
broken otffo blunt as to thew, that it mull probably 
have extended four or five inches farther. In this fo- 
lid part c hand many fmall teeth in rows, but not quite 
regular ; fome rows having but two, fome three, and 
others four. They begin an inch diftant from the 
chanel, and went probably to the extremity that is 
broken 
