PLATE 34. 



Geodia agassizii Lendenfeld (young) from Station 4228. 

 Figures 1-17. 



1-16. — Orthoplagiotriaenes and orthoplagiotriaene-derivates; magnified 30; phot. Zeiss, planar 20: 

 1-7, orthoplagiotriaenes with the rhabdome pointed at the acladomal end; 



8, 10-12, 14, orthoplagiotriaenes with the rhabdome slightly shortened and rounded and more 



or less thickened at the acladomal end; 



9, orthoplagiotriaene with the rhabdome slightly shortened and simply rounded at the acladomal 



end; 



13, amphiclade orthoplagiotriacne-dcrivate with the rhabdome shortenetl, rounded, thickened, and 

 provided with a spine-like opisthoclade at the acladomal end; 



15, orthoplagiotriaene-derivate with one clade bifurcate and the rhabdome much shortened, and 



rounded and thickened at the acladomal end; 



16, mesoclade orthoplagiotriaene-derivate. 



17. — Transverse section of the specimen; magnified 1.6; phot. Zeiss, planar 100. 



Geodia mesotriaenella Lendenfeld. 

 Figures 18-26. 



18. — Group of asters from a centrifugal spicule-preparation ; magnified 300; u. v. phot. Zeiss, q. monochr. 



1.7: 



a, large oxyasters; b, small strongylosphaerasters. 



19. — View of the sponge; natural size; phot. Zeiss, anastig. 480 / 412. 



20. — Portion of the surface bearing afferent pores, a superficial para tangential section viewed with trans- 



mitted light; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 



21. 22. — Large oxyastcr; magnified 1800; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 



21, focused higher; 22, focused lower. 



23. — A sterraster; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 



24. — A large oxyaster; magnified 1800; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. • 



25. — Portion of the surface bearing efferent pores, a superficial paratangential section viewed with 



transmitted fight; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6_. 



26. — Group of small strongylosphaerasters from a centrifugal spicule-preparation; magnified 1800; 



u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10 : 



a, with longer rays attenuated towards the end; b. with shorter cylindrical rays. 



