PLATE 73. 



Hyalonema (Prionema) agujanum tenuis Lendenfeld. 



Figs. 1-6 — form A. 

 Fig. 7 —form B. 



1. — Front-view of the tip of a tooth of a macramphidisc of form A; magnified 500; phot. Zeiss, H. I. 



apochr. 2, compens. oc. 6. 



2, 3. — Front-view of the tip of a tooth of a macramphidisc of form A; magnified 2000; u. v. phot. Zeiss, 



q. monochr. 1.7, q. oc. 10: 



2, focussed lower; 3, focussed higher. 

 4. — Half of a macramphidisc of form A; magnified 500; phot. Zeiss, apochr. 4, compens. oc. 12. 

 5-7. — Macramphidiscs; magnified 500: 



5, 6, of form A; 



7, of form B; 



5, phot. Zeiss, apochr. 8, compens. oc. 8; 



6, 7, phot. Zeiss, apochr. 4, compens. oc. 6. 



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