336 Jlf. Home's Defcription of 
longitudinal, making a band the whole length of the body, on; 
the edge of which the tranfverfe fibres running acrofs the back: 
terminate. 
The two cartilaginous fubftances by which the animal ad- 
heres to its (hell, are placed one on each fide of the body, and are 
joined together upon the back of the animal at their pofterior 
edges : they are about three-quarters of an inch long, are very 
narrow at their anterior end, becoming broader as they go 
backwards ; and at their pofterior end they are the whole 
breadth of the body of the animal. Upon their external fur- 
face there are fx tranfverfe ridges, or narrow folds;: and along 
their external edges, at the end or termination of each ridge,, 
is a little eminence refembling the point of a hair pencil, fa- 
that on each fide of the animal there are fix of thefe little pro- 
jecting feuds, for the purpofe of adhering to the fides of the fhelF 
in which the animal is inclofed. The internal furfaces of 
thefe cartilages are firmly attached to the body of the animal, in- 
their middle part, by a kind of band or ligament ; but the upper; 
and lower ends- are lying loofe. 
From the end of the body, between, the two upper ends of f 
thefe cartilages, arife what I fuppofe to be the tentacula, confift- 
ing of two cones, each, having a fpiral membrane twining round 
it : they are clofe to each other at their bafes, and diverge as 
they rife up, being about an inch and a quarter in length, and ' 
nearly one-fixth of an inch in thicknefs at their bafe, and gra— 
dually diminifhing till they terminate in points*- The mem- 
branes which twine round thefe cones alfo take their origin * 
from the body of the animal, and make five fpiral turns and a 
half round- each, being loft in. the points of the cones ; they 
are loofe from the cone at the loweft fpiral turn which they- 
make, and are nearly half an inch in. breadth; they are exceed- 
