HEXACTINELLIDA. 13 
Autodermalia hexactins; oxypentactine hypodermalia with rough or smooth 
surface and without prickles ; oxyhexasters with extremely slender rays. 
The single specimen representing the above species is in a bad state of preserva- 
tion, the five half-macerated fragments of grayish colour being saturated with mud. 
Mr. Hodgson gives the information that on the return voyage the trawl was put 
overboard and dragged for some distance over a dead level bottom of mud, but that 
at one spot the trawl passed over a patch of stones dropped by an iceberg. This 
would account for the condition of the specimen. With some difficulty the fragments 
were pieced together in the manner shown on PI. III., fig. 4; there was no doubt 
about the base with its small but indubitable root-tuft, nor about the oscular end, but 
possibly a fragment may be missing from the intervening part; enough remains, 
however, to show that the sponge was narrow at the orifice and broader at the lower 
end than above. The specimen, as made up, is 16 em. in length, and 5 cm. in breadth 
below the middle. The orifice, which is 1°5 em. in diameter, is partly surrounded by 
diactin marginalia projecting about 1°5 em. The root-tuft is formed of dense tufts of 
basalia caked with mud at the ends. The velum has been mostly rubbed away ; but 
patches of it exist, especially in the fragment bearing the oscule. The gastral 
membrane is continuous. 
Skeleton.—The framework is formed of bundles of thin slender diactins. 
Spicules.—The principalia are diactins very long and slender, averaging 
3500 x 1°*5u, mostly entirely smooth, and with sharp-pointed ends, though some are 
slightly roughened at the ends. 
The autodermalia (VI. 1a) are hexactins, with rather sharp-pointed rays each 
154 x 12y, and spined throughout; the hexactins give a pilose appearance to the 
surface, especially when viewed under a lens. 
The hypodermalia are oxypentactins, orthotropal, and mostly with straight 
smooth rays, each about 900 x 20u; others are larger, 1000 x 25p (VI. 1b, b’), 
with slightly curved wavy rays. a 
The autogastralia (VI, 1c) are hexactins, considerably larger than the auto- 
dermalia, each ray being 319p in length, and 11°25 in breadth at the base, tapering 
to a sharp point, and only sparsely spined. 
The intermedia include holoxyhexasters (VI. 1d), hemioxyhexasters (VI. 1d’), 
and only rarely monoxyhexasters (VI. 1d’), about 110-1254 in diameter; the 
primary rays are 8—10p in length; and the secondary rays are extremely slender. 
The caleycocomes (VI. le), 426 in diameter, have short primary rays, 13 in 
length, continuing each into a long solid capitulum 40y in length and 16, in breadth, 
whence originates a circle of eight to ten finely spined knob-tipped secondary rays. 
The holodiscohexasters (VI. 1f, f') of medium size, 125 in diameter, with 
short primary rays dividing into four or five disk-tipped secondary rays, oceur 
only rarely. 
The microdiscohexasters (VI. 1g), 48 in diameter, have their primary rays, 
Oat 
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