368 Proceedings of the Royal Society 
first pair of pinnules; and this peculiarity distinguishes them from 
Ant. phalangium. 
l^one of the cirri of Ant. liystrix reach the size of those borne by 
the smaller examples of Ant. prolixa. Many of these have a short 
dorsal spine on the distal edge which projects forwards over the 
base of the next joint, just as in the more centrally placed cirri of 
Ant. liystrix. 
Ant. eschrichti is described in the “Porcupine” reports as abundant 
in the cold area. The only record which I have of its occurrence, 
however, is Station 57 (1869), 632 fathoms. But whether^?^f. liystrix 
occurred here or not, we may assume with tolerable certainty that it 
is a “ cold area ” species ; for the “ Triton ” specimen was obtained 
at a station where the temperature was below 0° C. 
10. Antedon lusitanica^ P. H. Carpenter, 1883. 
Formula, A. 10. (2). “ . 
c 
Centrodorsal hemispherical, roughened at the dorsal pole, and 
bearing about a dozen slender cirri which reach nearly 30 mm. in 
length. They have about fifty joints, of which the first three or 
four are quite short, the next three much longer, and the following 
ones longer than wide, but gradii ally diminishing up to the fifteenth 
or twentieth joint. From this point (or earlier) to the end of the 
cirrus the joints have a well-marked dorsal spine, which is slightly 
less distinct in those just preceding the terminal claw. Ten arms, 
or (rarely) two distichals not united by syzygy. First radials 
scarcely visible except sometimes at the angles of the calyx. The 
second short and trapezoidal, with a strong median ridge, which is 
continued on to the axillaries. These are just pentagonal with 
slight backward projections into the second radials, and their sides 
are much flattened. This is still more marked on the outer sides 
of the first brachials, which are longer than their inner sides. The 
second brachials project more or less backwards into the first, 
and the third is a syzygial joint, the next three squarish, and the 
following ones more elongated with very oblique ends. The second 
brachials bear moderately long pinnules of about fifteen broad 
joints. The lowest have very prominent dorsal keels which are 
