HYALONEMA (LEPTONEMA) CAMPANULA. 
249 
I was unable to measure a number large enough to make the curves perfectly 
reliable, I shall not divide them into subgroups. 
The rnacramphidiscs (Plate 81 , figs. 7-10) are 150-290 m long, most fre- 
quently about 250 /x. The shaft is straight or more or less, sometimes very 
considerably, curved, and 1.5-5 /x thick. It is thickened gradually towards the 
ends and more abruptly at or near the centre to a tyle 2.8-7 n in transverse 
diameter, that is 1-3 n more than the adjacent parts of the shaft. A few spines, 
1-3 m long and 1-2 /x thick, forming a verticil arise from the central tyle. The 
remaining parts of the shaft are quite smooth or bear only one or a few small 
spines. 
The terminal anchors are 48-84 n long, about two sevenths of the whole 
spicule, and 25-53 m broad. The proportion of their length to their breadth is 
100 to 46-69, on an average 100 : 57.8. The anchors are composed of eight teeth. 
The individual teeth are 9-12 n broad, hardly at all attenuated distally, and 
simply rounded at the end. They arise vertically from the shaft and are, at a 
distance of about one eighth of their length from the point of origin, abruptly 
and very strongly bent toward the shaft. The part beyond this bend, that 
is the distal seven eighths, is either quite straight or somewhat bent outward; 
rarely the end is slightly bent inwards. These long distal parts of the teeth are 
divergent and enclose angles of 9° or 10° with the axis of the shaft. 
The mesamphidiscs (Plate 81, figs. 23, 24) are 77-118 \x long, most frequently 
about 84 ix. The shaft is straight and 4-7.5 m thick. It thickens gradually 
towards the ends, which are usually 3-4.5 n thicker than the middle-part. There 
is either no central thickening at all, or it is quite insignificant, not exceeding 
the adjacent parts of the shaft by more than 1 ^ in thickness. The shaft bears 
a few terminally rounded spines 3-8 tx long and 2-5 /x thick, which do not form 
a central verticil, but are scattered irregularly over its middle-part. Sometimes 
only a single large spine arises from the shaft. 
The terminal anchors are 30-43 /x long, about a third of the whole spicule, 
and 40-47 /x broad. The proportion of their length to their breadth is 100 to 
100-133, on an average 100 : 109. The anchor-teeth are in the medium-sized 
mesamphidiscs about 9 /x broad. They are attenuated distally, terminally 
rounded, and curved toward the shaft throughout their length. This curvature 
is much greater in their proximal than in their distal portion, and on the whole 
such that their end-parts diverge. 
The micramphidiscs (Plate 81, figs. 21, 22) are 18-26 /x long, most frequently 
about 24.5 /x. The shaft is straight and 0.9-1. 4 /x thick. A slight, not well- 
