1 



PLATE 40. 



Geodia ovis Lendenfeld. 

 Figures 1-30. 



1-4. — Orthotriaenes; magnified 10; phot. Zeiss, planar ,50. 



5. — View of a thick radial slice of the sponge; magnified 1.5; phot. Zeiss, anastig. 480 / 412: 



a, spicule-fur; b, cortex; c, choanosome. 

 6-13. — Large amphioxes; magnified 10; phot. Zeiss, planar 50. 

 14-16. — Sterrasters; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 



14, a side-view; 



15, 16, front-views of the umbilical side. 



17, 18. — The umbilical part of the surface of a sterraster: magnified 1800; u. v. phot. Zeiss, q. monochr. 

 1.7, q. oc. 10: 

 17, focused lower; 18, focused higher. 

 19-23. — Cladomes of orthotriaenes; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 2. 



24. — Part of the surface of a sterraster opposite the umbilicus; magnified 1800; u. v. phot. Zeiss, q. 



monochr. 1.7, q. oc. 10. 



25. — Part of an afferent pore-sieve; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 



26. — Tip of an abnormal spicule with numerous branch- rays; magnified 100; phot. Zeiss, apochr. 16, 



compens. oc. 6. 



27. — Tip of a normal, large amphiox; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 



28. — The cut face of the halved specimen; reduced 1 : 0.76; phot. Zeiss, anastig. 480 / 412. 



29. — Sterroid; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 



30. — The tip of an orthotriaene-clade with abnormally branched axial thread; magnified 100; phot. 



Zeiss, apochr. 16, compens. oc. 6. 



I 



