185 
series of the narrow adoral part. There are thus four distinet series 
of pores in the adoral part of the ambulacra. The buccal membrane 
contains numerous small, irregular spicules (Fig. 19); in young spec- 
imens a single larger, fenestrated plate may be found lying off each 
ambulaerum, in larger specimens this plate has disappeared. The 
plates of the periproct are covered with small spines. 
It is a noteworthy faet that the 
specimens turn green on preserv- 
ation in aleohol, as is the case also 
with the Clypeastrids. The largest 
specimen in hånd measures 50 mm 
in lenght. 
The pedicellariæ are mentioned 
only by H. L. C1 a r k, who has found 
them to be very scarce and only of 
three kinds, viz. tridentate, triphyl- 
lous and ophicephalous. There is, 
however, great variation as regards F '£- 19 1>lates from the bucal memb - 
. . rane of Echinobrissus recens in their 
their numbers; sometimes they are naturai position. i35 /i. 
very numerous, especially in young- 
er specimens, but also in fullgrown specimens they may be quite 
numerous. Besides the three forms, mentioned by Clark, I find 
also globiferous pedicellariæ to occur in this species. 
The globiferous pedicellariæ, which are especially numerous in 
the younger specimens, have a very peculiar structure (PI. VIII, 
Figs. 6 — 8). The valves are almost triangular, the comparatively 
narrow basal part passing, without any constriction, direetly into 
the blade, which is broad, open. There is a fairly large tooth at 
each outer corner and 3—4 somewhat smaller teeth betweeen 
these at the outer edge, which is straight cut, not produced to 
carry an end tooth. The giands apparently have not the shape 
of distinetly limited sacs but only consist of some glandular tissue, 
situated round the outer end of the valves; but this cannot be 
ascertained without a careful, histological examination for which my 
material is not fit. There is no neck; the stalk is compact, rather 
robust, ca. 0,5 mm long. These pedicellariæ, with their large, 
generally brownish heads, therefore, are very conspicuous among 
the short spines. The tridentate and ophicephalous pedicellariæ 
