Bd VI: 4) 
THE ECHINOIDEA. 
97 
Those below the petaloid part contain numerous spicules. The subanal tubefeet are 
rudimentary. In the tubefeet round the peristome the spicules are richly developed; 
they have the form of slender, slightly branched rods (PL XIX. Fig. 9). The rods 
supporting the filaments of these tubefeet are somewhat thick, but otherwise of the 
common simple structure. 
The pedicellariae are represented by three forms, viz. globiferous, rostrate and 
tridentate. The globiferous pedicellariæ (PI. XIX. P'igs. 3, 14, 20, 24) are generally 
very conspicuous, longstalked and with the head and the upper end of the stalk 
enclosed in a thick, probably glandular, coat. The valves end in two (seldom three) 
long teeth, gently curved at their base. The blade is narrow, with a long slit in 
the outer half, the lower part being a closed tube; its lumen continues some way 
down into the basal part. There is no neck; the stalk has a little swelling, where 
the muscles from the head are fastened, otherwise without widenings; it is of rather 
compact structure. This form of pedicellariæ is especially numerous along the petals. 
(In Abatus cavernosus var. bidens a quite similar form of globiferous pedicellariæ is 
found; cf. above p. 73, PI. XIX. Figs. 32, 39.) — The rostrate pedicellariæ (PI. XIX. 
Fig. 19) are very like those of Abatus; they are rather small, only ca. 0.2—3 mm. 
length of head. The tridentate pedicellariæ (PI XIX. Figs. 13, 23, 25, 2 7) are three- 
valved, seldom two-valved; they reach a rather large size, up to 0.8 mm. length of head. 
The valves join only in the outer part, in about one third of the length of the blade; 
below they are widely apart. The outer part of the blade is widened, with finely 
serrate edges, the lower part is narrow, forming a closed tube below, with a broad 
slit continuing down from the widened part. The border between the two parts of 
the blade is sharply marked, the side edges being bent inwards over the blade and 
making rather sharp corners. The edges of the lower part of the blade are smooth, 
as are also the edges of the basal part and the apophysis. The neck is well devel- 
oped, except on the largest specimens, where it may be almost wanting. The stalk 
is compact, with no distinct widenings. In the smaller tridentate pedicellariæ the 
narrow part of the blade becomes gradually shorter, and the quite small ones are 
simply leafshaped (PI. XIX. Fig. 8). These latter may equally well be termed tri- 
phyllous pedicellariæ. — The sphæridiæ are round, rather much grooved (PI. XIX. 
Fig- 4 )- 
As stated above, the females have their petals transformed into marsupia, and, 
fortunately, the embryos were also found in the marsupia. As in Abatus caverno- 
sus , I have found both eggs and large embryos, almost fully developed, in the same 
marsupium; in one I counted 7 eggs and 10 embryos, in another marsupium 11 eggs 
and 6 embryos. The eggs are yellow, evidently very rich in yolk, 1 mm. in dia- 
meter. Most of the embryos were about 2 mm. long, a few of them a little smaller 
13 — 100133. Schwedische Südpolar-Expediticn içoi — cçoj. 
