418 THE DEPTHS OF THE SEA. (CHAP. 1X. 
and other impurities thus removed, the skeleton 
comes out a lovely lacy structure of the clearest 
glass. The six-rayed form of the spicules gives the 
network which is the result of their fusion great 
flexibility of design, with a characteristic tendency, 
however, to square meshes. ° 
On the 30th of August, 1870, Mr. Gwyn Jeffreys 
dredged in 651 fathoms in the Atlantic off the mouth 
of the Strait of Gibraltar an exquisite sponge, 
resembling /7oltenia in its general appearance, but 
differing from it in the singular and beautiful cha- 
racter of having a delicate outer veil about a centi- 
-metre from the surface of the sponge, formed by the 
interlacing of the four secondary rays of large five- 
rayed spicules, which send their long shafts from that 
point vertically into the sponge body (Fig. 65). The 
surface of the sponge is formed of a network of large 
five-radiate spicules, arranged very much as in Hol- 
tenia; but the spicules of the sarcode-—the small 
spicules which are embedded in the living sponge-jelly 
—are of a totally different form. A single large 
‘osculum’ opens, as in Loltenia, at the top of the 
sponge, but instead of forming a cup uniformly 
lined with a netted membrane, the oscular cavity 
divides at the bottom into a number of branching 
passages as in Pheronema anne, described by Dr. 
Leidy. JI was inclined at first to place this species 
in the genus Pheronema, but Dr. Leidy’s descrip- 
tion and figure are by no means satisfactory, and 
may refer to some other form of the [oltenia group. 
The spicules of the ‘ beard’ are more rigid and thicker 
than those of Holtenia, and seine among them 
are some very large four-barbed grappling hooks. 
