PLATE 51. 



Hyalonema (Phialonema) pateriferum Wilson. 

 Figures 1-28. 



1. — View of the specimen; natural .size; phot. Zeiss, anastig. 480/412 mm. 



2. — Groups of large macramphidiscs from a spicule-preparation; magnified 100; phot. Zeiss, apochr. 



16, compens. oc. 6. 

 3-6. — Small micramphidiscs; magnified 500: 



3, 5, phot. Zeiss, H. I. apochr. 2, compens. oc. 4; 



4, 6, phot. Zeiss, apochr. 4, compens. oc. 12. 

 7-12. — Large micramphidiscs; magnified 500: 



7, 8, 10-12, phot. Zeiss, H. I. apochr. 2, compens. oc. 4; 

 9, u. V. phot. Zeiss, q. monochr. 6, q. oc. 7. 

 13, 14. — A large micramphidisc; magnified 500; phot. Zeiss, H. I. apochr. 2, compens. oc. 4: 

 13, focussed higher; 14, focussed lower. 



15. — Side-view of a small macramphidisc, with regular anchors; magnified 500; u. v. phot. Zeiss, q. 



monochr. 6, q. oc. 7. 



16. — Side-view of a large macramphidisc with spirally twisted anchors; magnified 500; phot. Zeiss, 



apochr. 4, compens. oc. 6. 



17. 18. — Side-views of large macramphidiscs; with regular anchors; magnified 500; phot. Zeiss, apochr. 



4, compens. oc. 6. 



19, 20. — Side-views of a large macramphidisc with regular anchors; magnified 500; phot. Zeiss, apochr. 

 4, compens. oc. 12: 

 19, focussed lower; 20, focussed higher. 

 21, 22. — Apical views of anchors of large macramphidiscs; magnified 500: 



21, u. v. phot. Zeiss, q. monochr. 6, q. oc. 7; 



22, phot. Zeiss, apochr. 4, compens. oc. 12. 

 23-28. — ■ Microhexactines; magnified 500: 



23, 24, 26, 28, ordinary microhexactines with strongly and regularly curved rays; phot. Zeiss, 

 apochr. 4, compens. oc. 12; 



25, an exceptionally large microhexactine with irregularly curved rays; u. v. phot. Zeiss, q. monochr. 

 6, q. oc. 7; 



27, a microhexactine with rays only slightly curved; phot. Zeiss, H. L apochr. 2, compens. oc. 4. 



