HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 
323 
of specimen of specimen of both speci- 
a b mens together 
limits 220-480 212—492> 212-492 
Length u 
most frequently about 240, 320, 468 | 277, 387, 468 468 
Shaft, thickness, limits yu 17-26 19-28 17-28 
transverse diameter of tyle, » limits 17-31 19-32 17-32 
Central 
tyle the tyle thicker than the shaft by u, 0-8 0-9 0-9 
limits 
‘length, limits 90-122 94-140 90-140 
| breadth, limits yp 148-195 140-210 140-210 
. proportion of anch-| limits 100 to 141-177 131-189 131-189 
Terminal 
h or-length to anchor- 
anchors | breadth average 100 to 161.4 158.6 160.1 
proportion of anch-|,._. ; ee 
or-length to total aes Ue ee 
length of whole spi- 
cule average 1: 3.2 
a stout knob or two are observed also on other parts of the shaft (Plate 85, 
pes: 1; 2). 
macramphidises, sometimes 21 » long and 14 w thick. 
The single large spine on the central tyle is, in the normal large 
I have never seen more 
than one such large spine on a normal spicule of this kind. In a few abnormal 
large macramphidises I observed (Plate 85, fig. 3) one or two clusters of verticils 
of projections arising some distance from the middle of the shaft. These had a 
maximum length of 45 », and were inclined or curved towards the centrum. 
They appear to be supernumerary anchor-teeth. 
The proportion of the terminal anchor to the total length of the whole spicule 
is (in both specimens together), as stated above, 1 to 2.1-3.9, an average of 1 : 3.2. 
The difference between total length and anchor-length is the greater the larger 
the spicule. In the large macramphidiscs 400 » and more in length the above 
proportion is 1 : 3.2-3.9, in those under 300 » in length 1 : 2.1—8. 
The anchor-teeth are about 30 » broad and pointed at the end. They arise 
nearly vertically from the shaft and are quite strongly curved in their proximal, 
and straight in their distal part. Their total curvature is such that their end- 
parts diverge at an angle of 12°-22° from the shaft. 
The chief dimensions of the small macramphidiscs (Plate 83, fig. 45c; 
Plate 84, figs. 3-13, 26-32) are: — 
