Mr. T. Higgin on Labaria hemispherica. 387 
there are no spined forms, from which it must be inferred 
that the spined anchoring-spicules noticed by Mr. Carter in 
his description of the British-Museum sponge belonged to 
a “ Meyerina claveformis,”’ as well as the bunch of spicules 
forming the “ fraudulent tuft,” and had been caught up acci- 
dentally, if not purposely stuck on to the specimen. ‘The 
smooth anchoring-spicule which is the one proper to the 
species is a fine “hair-like spicule, 8 to 4 inches in length; 
it tapers from its middle to a fine point at its fixed end, “and 
also gradually diminishes to within a short distance of its free 
end, measuring there only 1-1000th of an inch, after which 
it quickly becomes flat, with a breadth of 1-300th of an inch, 
and ends in two opposite hooks, recurved like the flukes of 
an anchor, as figured by Mr. Carter (‘Annals,’ 1873, ser. 4, 
vol. xil. pl. xiv. fig. 2), the entire spread of the ” anchor 
measuring 1-45th of an inch (PI. XXII. fig. 3 4). 
The spicules of the whisker-like tufts are plain, fusiform, 
in length about 34 inches, with a diameter of 8-500ths of an 
inch at the middle or thickest part. 
The spicules of the erect fringe round the labrum, all more 
or less broken at the free end, are also fusiform, and, as they 
exist at present, are smooth throughout ; but there is an appear- 
ance of spines on some towards the free end, and therefore 
in their perfect state they may perhaps be furnished with short 
conical spines towards the points. The largest are about one 
inch long, with a diameter in the middle of 1-750th of an 
inch. 
The spicules of the surface-reticulation are of four kinds :— 
1, large nail-like spicules (that is, smooth pointed shafts) with 
four equally smooth arms projecting opposite or at right angles 
to each other from the heads of the shafts, the arms inclined 
slightly downwards or inwards; these spicules are of various 
sizes, from the large form, plainly visible to the unassisted 
sight, down to others of PcTOSCOpIC minuteness ; the shafts 
of the larger spicules are 4 an inch in length ; the arms may 
be the same, but most frequently they are of different lengths ; 
and sometimes one of them is blunt, not at all pointed, and 
not more than 1-12th of an inch long: the shafts and arms 
measure at the cross about 1-48th of an inch in diameter ; 
2, long, slender, acerate spicules, thickly covered with short 
sharp spines, all pointing towards one and the same end of 
the shaft; 3, smooth acerates, with the cross on the central 
canal; 4, plumose spicules of shapes intermediate between 
one with a very thick shaft, short and bushy-looking, with 
long, strong, bluntly ended arms (Pl. XXII. fig. 5), and 
another with small, short, fine arms and a long feather like 
