PLATE 44. 



Hyalonema (Hyalonema) agassizi Lendenpeld. 



Figs. 1-20, 22-24, 30 

 Figs. 21, 25, 27 

 Fig. 26 

 Figs. 28, 29 



form A, Station 4656. 

 form B, Station 4651. 

 form C, Station 4740. 



form D, Station 3684 (A. A. 17). 



1-5. — Marginal diactine pinnies 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. oc. 6. 



6-10. — Fai'ts of the stoutest portions of micinate amphioxes of form A; magnified 2000; u. v. 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 focussed 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. Zei.ss, q. monochr, 



6, q. oc. 7. 



16. — The central part of a microhexactine of form A; magnified 2000; u. v. phot. Zeiss, q. monochr. 



1.7, q. oc. 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. monochr. 



6, q. oc. 7. 



21-23. — Microhe.xactines with more or less curved rays; magnified 500; phot. Zeiss, H. I. apochr. 2, 

 compens. oc. 4: 



21, of formB; 



22, 23, of form A. 



24. — Microhexactine-derivate diactine of form A; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. 

 oc. 4. 



25-28. — Microhexactmes; 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. oc. 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. 



