PLATE 89. 



Hyalonema (Oonema) sequoia Lendenfeld. 

 Figures 1-36. 



]-.'). — Large superficial amphioxes (tignules); magnified 20; phot. Zeiss, planar 20 mm. 

 (1-14. — Large micramphidiscs; magnified 500: 



6, 7, 9-14, phot. Zeiss, H. I. apochr. 2, compens. oc. 6; 

 8, phot. Zeiss, apochr. 8, compens. oc. 12. 

 15. — Group of spicules from a spicule-preparation of the superficial part of the body; magnified 20; 

 phot. Zeiss, planar 20 mm.: 



a, slender amphioxes; b, stout amphioxes; c, large superficial pinnies; d, small macramphi- 

 discs; e, large amphidiscs, probably of H yalonema agassizi and foreign to the sponge, which 

 are remarkably frequent. 



Ifi-lO. — An abnormal amphidisc with reduced anchors; magnified 500; phot. Zeiss, H. I. apochr. 2, 

 compens. oc. 6: 



16, one end, focussed high; 



17, the whole spicule, focussed lower; 18, focussed still lower; 

 19, the other end, focussed lowest. 



20-30. — Small micramphidiscs; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 6. 

 31, 32. — End-parts of anchor-teeth of large macramphidiscs; magnified 500: 



31, ]ihot. Zeiss, apochr. 8, compens. oc. 12; 



32, phot. Zeiss, apochr. 8, compens. oc. 6. 



33. — A somewhat abnormal small macraniphidisc; magnified 500; phot. Zeiss, apochr. 8, compens. 



oc. 12. 



34. — A small micramphidisc ; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 



35. 36. — An abnormal small macramphidisc ; magnified 500; phot. Zeiss, apochr. 8, compens. oc. 12: 



35, focussed higher; 36, focussed lower. 



