THE ELOSCTTLES. 
165 
Dr. Dobie bad observed,* in Flosc. cornuta, immediately 
below tbe integuments, groups and lines of very small granules 
continually in a state of rapid molecular motion, in appearance 
exactly resembling tbe molecules in the cusps of Glosterium. 
Besides tbe molecular, they are subject to another motion, for 
occasionally they move from one part of tbe surface to another, 
in currents not very distinct nor persistent, and in no definite 
direction. He has seen these granules running in lines down 
tbe foot, and collecting in groups. 
In both this species and in F. ornata there are to be seen 
web-defined clear bands permeating tbe disk in a symmetrical 
manner ; and in a specimen of tbe latter I saw that these are 
very distinctly vessels, with wabs, in which minute globular 
granules are suspended in a hyaline fluid. (See plate ix., 
fig. 1.) They have no proper circulatory motion, but the 
muscular movements of the animal change the position of the 
granules, and drive them to and fro, so that the form, direc- 
tion, and dimensions of the canals can be easily perceived. 
Especiaby in the moment of expansion, after the contractions, 
which are almost every instant occurring in this sensitive 
creature, the granules are propebed with force up the canals, 
and in particular through the central vessel of the dorsal ray of 
the petaloid disk into the angle, where they accumulate, and 
thence through a circular vessel around the edge of the terminal 
knob. In this latter vessel a tremulous motion often remains 
among the granules after those in the other vessels have 
subsided to rest. The order of the vessels, so far as they can 
be discerned in the dorsal aspect, is as fobows : — -A rather wide 
vessel encircles the neck or constriction below the disk; 
thence perpendicular tubes, one in the centre of each petal and 
one intermediate, go off to join the marginal vessel of the disk, 
which fobows the direction of the edge, and which sends off 
smab circular vessels to the terminal knobs. From the lower 
side of the cervical vessel similar branches proceed downwards, 
and join a transverse but undulating vessel that appears to run 
along the line at which the granular and sensitive membrane 
relinquishes its contact with the internal skin of the body, and 
folds inwards to form the first diaphragm. Posterior branches 
are in turn given off from this, which interlace and anastomose 
in their course down the wabs of the body, forming a loose 
network, with long meshes (much less distinct, however, than 
those of the anterior region), which unite at length into a 
single vessel that penetrates the slender elongated foot, even 
to its extremity, for I saw a single granule of the same kind as 
those of the anterior vessels close to the base of the foot, and 
a cluster of them a little below the junction of the body. 
* “ Annals Nat. Hist.) Oct. 1849.” 
