HYALONEMA (LEPTONEMA) CMIPANULA. 249 



I was unable to measure a number large enough to make the curves perfectly 

 reliable, I shall not divide them into subgroups. 



The macramphidiscs (Plate 81, figs. 7-10) are 150-290 fi long, most fre- 

 quently about 250 yu- The shaft is straight or more or less, sometimes very 

 considerably, curved, and 1.5-5 fi 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 m more than the adjacent parts of the shaft. A few spines, 

 1-3 n long and 1-2 ^ 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 

 spmes. 



The terminal anchors are 48-84 /j. 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 indi\adual teeth are 9-12 fi 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 ?nesamphidiscs (Plate 81, figs. 23, 24) are 77-118 m long, most frequently 

 about 84 /Li. The shaft is straight and 4-7.5 m thick. It thickens gradually 

 towards the ends, which are usually 3^.5 m 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 fi in thickness. The shaft bears 

 a few terminally rounded spines 3-8 /^ long and 2-5 n 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 yu long, about a third of the whole spicule, 

 and 40-47 m 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 ix 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 ^ long, most frequently 

 about 24.5 yu. The shaft is straight and 0.9-1.4 n thick. A slight, not well- 



