PLATE 44. 
Hyalonema (Hyalonema) agassizi LeENDENFELD. 
Figs. 1-20, 22-24, 30 —form A, Station 4656. 
Rigs, 21 25, 27 —form B, Station 4651. 
Fig. 26 —form O, Station 4740. 
Figs. 28, 29 —form D, Station 3684 (A. A. 17). 
1—5.— Marginal diactine pinules of form A: 
1, 2, two smaller ones; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6; 
3, 4, the distal parts of two larger ones; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6; 
5, a larger one; magnified 100; phot. Zeiss, apochr. 16, compens. oe. 6. 
6-10.— Parts of the stoutest portions of uncinate amphioxes of form A; magnified 2000; u. " phot. 
Zeiss, q. monochr. 1.7, q. oc. 10: 
6, part of an uncinate focussed lower; 7, the same focussed higher; 8, part of another uncinate 
focussed lower; 9, the same foctiseed higher; 10, part of a third uncinate. 
11, 12.— The distal end-parts of two uncinates of form A; magnified 500; phot. Zeiss, H. I. apochr. 2, 
compens. oc. 4. 
13, 14.— Two uncinates of form A; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 
15.— A microhexactine with fairly straight rays of form A; magnified 500; u. v. phot. Zeiss, q. monochr. 
( Ch, Cs Wo 
16.— The central part of a microhexactine of form A; magnified 2000; u. v. phot. Zeiss, q. monochr. 
17, Geocy 10; 
17.— Group of spicules from a centrifuge spicule-preparation of form A; magnified 200; phot. Zeiss, 
apochr. 8, compens. oc. 6: 
a, uncinate amphioxes; b, regular microhexactines; c, irregular microhexactine with two 
rays much longer than the others; d, micramphidiscs. 
18, 19.— Part (three rays and centre) of a regular microhexactine of form A; magnified 2000; u. v. 
phot. Zeiss, q. monochr. 1.7, q. oc. 10: 
18, focussed higher; 19, focussed lower. 
20.— A microhexactine with nearly straight rays of form A; magnified 500; u. v. phot. Zeiss, q. monogla 
(Cl OG te > 
21-23.— Microhexactines with more or less curved rays; magnified 500; phot. Zeiss, H. I. apochr. = 
compens. oc, 4: 
21, of form B; 
22, 23; ot form A. 
24.— Microhexactine-derivate diactine of form A; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. 
oc. 4. 
25-28.— Microhexactines; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 4: 
25, 27, of form B; 
26, of form C; 
28, of form D. 
29.— Part of a microhexactine of form D; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oe. 4. 
30.— Part (one ray and centre) of a microhexactine of form A; magnified 2000; u. v. phot. Zeiss, q. 
monochr. 1.7, q. oc. 10. 
