PLATE 34. 



Geodia agassizii Lendenfeld (young) from Station 4228. 



Figures 1-17. 



1-16. — Orthoplagiotriaene.s and orthoplagiotriacne-tlerivates; magnified .'50; phot. Zei.ss, planar 20: 

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

 S, 10-12, 14, orthoplagiotriaenes with the rhabdorae slightly shortened and rounded and more 



or less thickened at the acladomal end; 

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



end ; 

 13, amphiclade orthoplagiotriaene-derivate witli the rhabdome shortened, rounded, thickened, and 



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

 15, orthoplagiotriaene-derivate w'ith one clade bifurcate and the rhabdome much sliortcned, and 



rounded and thickened at the acladomal end ; 

 1(), mesoclade orthoplagiotriaene-derivate. 

 17. — Transverse section of the specimen; magnified 1.6; phot. Zei-iis, planar 100. 



Geodia mesotriaeneUa Lendenfeld. 

 Figures 18-26. 



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

 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 paratangential section viewed with trans- 

 mitted hght; magnified 100; phot. Zeiss, apochr. 16, compens. oc. (i. 



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

 21, focused higher; 22, focused lower. 



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



24. — A large oxyaster; magnified 1800; u. v. phot. Zeiss, q. monoclir. 1.7, i\. oc. 10. 



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

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



26. — flroup of small strongylosphaerasters from a centrifugal spicule-preparation; niagnifieil 1800; 

 u. V. [)hot. Zeiss, q. monochr. 1.7, q. oc. 10 : 



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



