258 THE ATLANTIC. [CHAP. IV. 
consisting of a slender central shaft, with a cross of four short 
transverse processes in the centre. The outer half of the cen- 
tral axis is delicately feathered. The lower surface of the 
sponge (Fig. 67) is protected by a singularly elegant net-work 
of sarcode, with wide oval and round meshes radiating irregu- 
larly from a central point. The membrane is traversed by ir- 
regularly radiating ridges of firmer substance, which unite in 
the centre in a projecting boss at the point where in this speci- 
men the “glass rope” has unfortunately been torn out. 
Fic. 66.—Hyalonema toxeres, WyvitiE Tomson. Upper surface, natural size. (No. 24.) 
In minute structure, /7yalonema toxeres corresponds in all 
essential respects with 7/7. Sieboldi and H. Lusitanicum. All 
the spicules are of the same ground-forms, with some little dif- 
ferences in detail, with the exception of one remarkable spicule 
which enters largely into the structure of //. toweres, and serves 
to distinguish even the smallest portion of it. This is a large 
spicule, the largest above a centimetre in length, and more than 
half a millimetre in width in the centre, shaped like a bow or 
