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HYALONEMA (PRIONEMA) PINULIFUSUM. 
in their distal and proximal portions. A more or less conspicuous conical spine 
with a maximum height of 0.5 n arises from the centre of the apex of the 
anchor. The anchors are very frequently irregular in so far as some teeth are 
considerably longer than the opposite teeth (Plate 106 , figs. 21-23, 25). 
The nearest ally to H. (P.) crassum is H. (P.) spinosum (p. 273). From this 
H. (P.) crassum differs chiefly: — by possessing macramphidiscs with short and 
broad anchors and smooth teeth ; by the anchors of the serrated macramphidiscs 
being somewhat differently shaped ; by the absence of the spicules there described 
as small macramphidiscs ; by the largest micramphidiscs attaining a much larger 
size; by the presence of stout paratangential rhabds (tignules) in the superficial 
membranes ; and by having longer pinules. 
Hyalonema (Prionema) pinulifusum, sp. nov. 
Plate 70, figs. 11-24; Plate 71, figs. 1-11; Plate 72, figs. 1-15. 
I establish this species for a fragment trawled off the south coast of western 
Panama at Station 4621 on 21 October, 1904; 6° 36' N., 81° 44' W. ; depth 1067 
m. (581 f.) ; it grew on a bottom of green mud and rock; the bottom-temperature 
was 40.5°. It possesses large pinules with distal rays greatly thickened in the 
middle and markedly fusiform in shape. To these the name refers. 
Shape and size. The specimen is a flat fragment, 14 cm. long, 8 cm. broad, 
and with a maximum thickness of 1 cm. The margin is lacerated. The speci- 
men is composed of lamellae about 1 mm. thick, separated by wide cavities. 
It probably formed part of a lamellar or cup-shaped sponge. 
The colour in spirit is brown. 
The skeleton. On many parts of the surface the pinule-fur is still more or 
less intact. A number of small wart-like protuberances, 0.5-1. 5 mm. broad 
and high, arise on one side of the lamellar body. These bear on their summits 
dense masses of medium-sized pinules. Much larger scattered pinules with 
stout, spindle-shaped distal ray arise from the walls of the wide depressions be- 
tween these protuberances. Pinules of the same kind densely cover the margins 
of some of the lamellae on the other side of the sponge. Other parts of the thin 
lamellae bear sparse, small pinules, with relatively few and small spines on the 
slender distal ray. Besides these three kinds of pinules, a fourth kind, with distal 
rays terminating in a rather long and slender terminal cone and with large second- 
ary spinelets on the primary spines of the distal ray, has been found quite 
frequently in the preparations. These pinules are identical with certain pinules 
