442, THE DEPTHS OF THE SEA. [CHAP. IX. 
crinoids, however, are not predatory animals. Their 
nutrition is effected in a very gentle manner. The 
grooves of the pinnules and arms are richly ciliated. 
The crinoid expands its arms like the petals of a full- 
blown flower, and a current of sea-water bearing 
organic matter in solution and suspension is carried 
by the cilia along the brachial and radial grooves 
to the mouth. In the stomach and intestine the 
water is exhausted of assimilable matter, and the 
length and direction of the excretory proboscis pre- 
vent the exhausted water from returning at once into 
the ciliated passages. 
The other West Indian Pentacrinus—P. miilleri— 
seems to be more common off the Danish Islands 
than P. asteria. The animal is more delicate in 
form. The stem attains nearly the same height, 
but is more slender. The rings of cirri occur about 
every twelfth joint, and at each whorl two stem- 
joints are modified. The upper joint bears the facet 
for the insertion of the cirrus, and the second is 
grooved to receive its thick basal portion, which 
bends downwards for a little way closely adpressed 
to the stem, before coming free. The syzygy is 
between the two modified joints, and in all the com- 
plete specimens which I have seen the stem is broken 
through at one of these stem syzygies, and the ter- 
minal stem-joint is worn and absorbed, showing 
that the animal must have been for long free from 
any attachment to the ground. 
On the 21st of July, 1870, Mr. Gwyn Jeffreys, 
dredging fiom the ‘ Porcupine’ at a depth of 1,095 
fathoms, lat. 39° 42’ N.,- long. 9° 43° W., with a 
bottom temperature of 4°3 C. and a bottom of soft 
