130 EURETE ERECTUM. 
times that the spines were arranged in elongate spiral rows; in other cases no such 
spiral arrangement could be made out. Often the spines are restricted to the 
distal and lateral sides of the rays; sometimes, however, they are also found on 
the proximal side. 
The irregular gastral pinule-derivates (Plate 30, fig. 3) are similar to the regu- 
lar pentactine-like ones and differ from them only in one or two of their lateral 
rays resembling the distal rays of pinules. 
The uncinates (Plate 31, figs. 13, 14) are slightly curved or nearly straight, 
pointed at both ends, 0.5-1.6 mm. long, and 4-9 » thick. Their spines are 7-274 
long, and 0.6-1 » thick at the base. They either diverge considerably (Plate 31, 
fig. 14) or are nearly parallel to the shaft (Plate 31, fig. 13). Their tips are 1.5— 
4 uw distant from the shaft. This elevation of their tips is by no means always in 
proportion to their length. 
The discohexasters (Plate 31, figs. 15, 18, 21) measure 50-70 u in total 
diameter. Their main-rays are regular, smooth, straight, 6-10 » long, and 1.6— 
3» thick. Hach main-ray bears from one to four end-rays. These are usually 
curved, concave to the continuation of the main-ray at the base, and nearly 
straight farther on. They are 18-26 uw long, 1.2-2 uw thick at the base, and 
attenuated distally to 0.8-1.5 uw. The end-rays bear along their length minute 
recurved spines, and at the end a terminal verticil of similar but larger spines, 
which together form a kind of terminal dise with deeply serrated margin 2.5-4 
in transverse diameter. 
It is possible that there are two kinds of discohexasters similar in size, but 
differing in respect to the end-rays, one with more slender and less spiny, the 
other with stouter and more spiny end-rays. Since, however, these asters are 
scarce I was unable to decide whether they all belong to the same series of forms, 
or whether two distinct varieties of them, as indicated above, should be distin- 
guished. 
The dermal scopules (Plate 31, figs. 16b, 17, 19) are 200-420 » long and 
consist of a centrum 4-10 » long and 5.5—-11.5 u broad, from which arises at one end 
(the inner) a simple shaft, and at the opposite (the outer) a bunch of end-rays. 
The centrum is not well-defined, often it passes quite gradually into the 
shaft. It and the proximal part of the shaft are densely covered with minute 
spines. The shaft is straight, cylindroconic, 170-330 u long, 3-6 « thick at the 
base, and pointed at the end. Sometimes, particularly in the dermal scopules 
with only two end-rays, this spinulation extends quite to the end of the shaft. 
Some of the dermal scopules have four end-rays, others only two, and a few have 
three. The dermal scopules with only two end-rays are fork-like. The end-rays 
