214 HYALONEMA (HYALONEMA) PLACUNA. 
less equal, or two larger and four more or less rudimentary rays. If this assump- 
tion is correct, and if the energy saved in the building of the smaller rays is 
utilised in increasing the size of the larger, the latter must be hypertrophic to 
a degree in proportion to the degree of reduction of the former as, in fact, 
they are. 
The amphidiscs. As these spicules are more numerous in form B than in 
form A, I shall commence the description of them with an examination of the 
amphidises of the former. 
The amphidises of form B are 18.5-367 » long. The frequency of those of 
different length is shown in Figure 9. 
Macramphidiscs 
eae 
Micramphidiscs Mesamphidiscs H ‘ 
ff Sern 7S peep 
A ' Small, with broad anchors —! ; : ' 
a ; ' H t ' 
File Large, with narrow anchors : 1 
A]: Small Medium Large Ais yi 
tre Yi alia ama ' Small} with! narrow anchors 
a pa 
Large, with broad anchors 
mo ne a ee ee ie ee 
Set A ee EO TEES pms, ee 
eee SS Sse Yah Se ee et ee 8s 
| | 
WO DMDAMNMOTAOOHODOAODDAOAADM HW rr C 
FH ANBARSFANRRRANHAASR RASA SSRESSRSH 
ZBHOBAAMNNDAOHHRHANDADSONSHNROGOKRDBAGSHDKROHOtHtOW 
SAANANAANANSHAHNTSTHTODSGRBSORBSOUNTOR OOK HOKSSDSS 
ms et et te st tt ON ON NT NN 09) 09) 0) 
ee Cee ee PEt clieii elie logh tte Tt | 
CUO MAMNNODHDOHTODOHORDONNAMHN KR OKROTHR 
Be NRA RN OR RSA SRR ERLES 
O~MDHAMNNASOHKRHAMOHAADONSCDAKONRSD On té ince) ee) 
BH ANNANDMOMNTT SD SORNDODSOUNT HER SSRHLKSSB 
Amt BM TTI NNNN MMO 
Fig. 9.— Form B. Amphidises. 
The figure shows that, apart from minor depressions of the frequency-curve, 
the amphidises can, biometrically (according to the frequency of those of different 
lengths), be divided into two main-groups, one comprising amphidises 18.5—48 yu 
long, the other amphidises 124-367 ». These groups dimensionally so very 
different are connected only by three of the 96 amphidiscs measured, which are 
55, 72, and 100 » long respectively. The part of the curve pertaining to the small 
amphidises exhibits three not very deep depressions, the part of it pertaining to 
the large amphidises one small and one considerable depression. The latter lies 
between amphidises 187 and 214 uv long. 
