PLATE 65. 
Hyalonema (Hyalonema) placuna LENDENFELD. 
Figs. 1, 3-138, 16-18, 23 —form B. 
Figs. 2, 14, 15, 19-22 —form A. 
1.— A terminal anchor of a macramphidise of form B, with a supernumerary tooth arising some distance 
below the others; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12. 
2.— Part of a mesamphidise of form A; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 
3-8.— Parts of a microhexactine of form B; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
3, the centrum and a ray of the spicule, focussed high (the tip of the ray in focus) ; 
4, part of the distal portion of the same ray, focussed lower (a region about 17 » from the tip in focus); 
5, part of the middle-portion of the same ray, focussed still lower (a region about 32 u from the tip in 
focus); : 
6, part of the middle-portion of the same ray, focussed still lower (a region about 42 » from the tip 
in focus); 
7, part of the proximal portion of the same ray, focussed still lower (a region about 53 » from the tip 
in focus); 
8, the basal part of the same ray and the centrum of the spicule, focussed lowest (the base of the 
ray in focus). 
9-12.— Small internal pinules of form B; magnified 300: 
9, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 
10-12, phot. Zeiss, apochr. 4, compens. oe. 12. 
13-15.— Micramphidises; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
13, a micramphidise of form B; 
14, a micramphidise of form A, focussed higher; 15, focussed lower. 
16—21.— Internal pinules; magnified 300: 
16-18, of form B; 
19-21, of form A; 
16, 20, 21, phot. Zeiss, apochr. 8, compens. oc. 12; 
17-19, phot. Zeiss, apochr. 4, compens. oc. 6. 
22, 23.— Radial sections through a superficial part of the sponge; magnified 30; phot. Zeiss, planar 
20 mm.: 
22, of form A; 
23, of form B; 
a, dermal pinule-fur; b, choanosome, 
