332 
HYALONEMA (OONEMA) CRASSIPINULUM. 
30 n. The proportion of anchor-length to anchor-breadth is 100 to 69-100, 
on an average 100 : 89.5. The teeth arise nearly vertically from the ends of 
the shaft, and are curved strongly at the base and decreasingly towards the 
end. The tips of the teeth are usually parallel or slightly divergent. 
The s?nall micramphidiscs (Plate 97 , figs. 21-28) are 24-57 i± long, most 
frequently about 32.4 /x. The shaft is 0.8-2 n thick, and generally centrotyle. 
The central tyle is 1.8-2. 6 n in transverse diameter, that is 0.3-1 n more than 
the adjacent parts of the shaft. Small spines are scattered over tyle and shaft- 
in the larger forms; in the smaller these spines are so minute that it is diffi- 
cult to make them out, often they appear to be absent altogether. The anchors 
are 7-22 n long, usually about a third of the whole spicule. The anchor-breadth 
is 7-19 ix. The proportion of anchor-length to anchor-breadth is 100 to 71-121, 
on an average 100 : 89.7. The teeth are sometimes remarkably numerous. 
They arise vertically from the ends of the shaft and are more strongly curved 
some distance from the base than proximally; beyond the strong bend, they 
decrease in curvature, so that their end-parts are nearly straight and parallel. 
The teeth are pointed at the end. 
The nearest allies of the above sponge are the species Hyalonema ( Oonema ) 
densum, H. (O.) sequoia, and H. (O.) crassipinulum described in this Report. 
From these it differs by being destitute of the large macramphidiscs. From 
H. (O.) densum also it differs by having straight-rayed micramphidiscs, and 
from the other two also by its superficial pinules being smaller and their distal 
rays much more slender. 
Hyalonema (Oonema) crassipinulum, sp. nov. 
Plate 92, figs. 1-23; Plate 93, figs. 1-10; Plate 94, figs. 1-33. 
One specimen of this species was trawled in the Central Pacific at Station 
3684 (A. A. 17) on 10 September, 1899; 0° 50' N., 137° 54' W. ; depth 4504 m. 
(2463 f.) ; it grew on a bottom of light yellow-gray Globigerina ooze. 
It possesses pinules with large, remarkably divergent spines on the proximal 
part of the distal ray. To this the name refers. 
Shape and size. The single specimen (Plate 93 , fig. 9) has the shape of an 
inverted bell, 105 mm. long, 95 mm. broad, and now strongly compressed later- 
ally and only about 18 mm. thick. In life the sponge was probably laterally com- 
pressed much less, or not at all. A stalk, 2.5 mm. thick and broken off rather 
short, protrudes from the lower rounded end. The lower and lateral surfaces, 
