PLATE 40. 
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Hyalonema (Hyalonema) cbtusum robusta LENDENFELD. 
Figures 1-22. 
1, 2.— Large macramphidises; magnified 500; phot. Zeiss, apochr. 4, compens. oe. 12. 
3-5.— Pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 
3, a gastral hexactine pinule; 
4, a dermal pentactine pinule with reduced lateral rays; 
5, a dermal pentactine pinule. ; 
6-15.— Microhexactines and ah crore oe ena magnified 500; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 4: 
6, 7, regular microhexactines; 
8, a pentactine microhexactine-derivate; 
9, a microhexactine with two opposite rays much longer than the others; 
10, a diactine microhexactine-derivate, the fully developed rays of which are not opposite; 
11, a triactine microhexactine-derivate; - 
12, 13, diactine (centrotyle), inicroheneenne-denvare the fully developed ae of which are 
opposite; 
14, 15, monactine (tylostyle or tyle) microhexactine-derivates. 
16, 17.— Small micramphidiscs; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 4. 
18.— A young micramphidise; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oe. 4. 
19.— Part of an irregular macramphidise; magnified 500; phot. Zeiss, apochr. 4, compens. oe. 12. 
20.— Group of microscleres from a centrifuge spicule-preparation; magnified 500; phot. Zeiss, H. I. 
apochr. 2, compens. oe. 4: 
a, small micramphidises; b, microhexactine; c, microhexactine-derivate with only two 
opposite, fully developed rays. 
21, 22.— Parts of the upper end of a large stalk-spicule; magnified 300; phot. Zeiss, apochr. 4, compens, 
oc. 6. ‘ 
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