PLATE 26. 



Geodia agassizii Lendenfeld (adult). 

 Figures 1-21. 



1-12. — Orthoplagiotriaenes and orthoplagiotriaene-derivates; magnified 20; phot. Zeiss, planar 

 20: 



1, a mesorthotriaene orthoplagiotriaene-derivate with simple, terminally abruptly bent clades, 



of a specimen from Station 2978; 



2, an amphiclade orthoplagiotriaene-derivate with three simple, very unequal clades and one opistho- 



clade a considerable distance from the cladomal end of the rhabdome, of a specimen from 

 Station 3168; 



3, an orthoplagiotriaene with oblique cladome and simple clades, of a specimen from Station 2886; 



4, a regular orthoplagiotriaene with short, simple clades, of a specimen from Station 2978; 



5, 6, 8, 12, orthoplagiotriaenes some or all the clades of which are terminally branched, of a speci- 



men from Station 4199; 



7, a regular orthoplagiotriaene with long simple clades, of a specimen from Station 2886; 



9, 10, 11, orthoplagiotriaenes some or all the clades of which are terminally branched, of a speci- 

 men from Station 3168. 



13. — Surface-view of a detached piece of the cortex of a specimen from Station 4199; magnified 7.5; 



phot. Zeiss, planar 50. 



14, 15. — An efferent cortical canal in a detached piece of an efferent area of the cortex of a specimen 



from Station 4199; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 



14, seen from within, the chonal sphincter, a, is in focus; an indistinct image of the dermal sieve, b, is 



seen behind; 



15, seen from without, the dermal sieve, b, is in focus; an indistinct image of the chonal sphincter, a, 



is seen behind. 



16-21. — Six specimens of the sponge; 16, 18-21, natural size, 17 reduced 1:0.67: phot. Zeiss, anastig. 

 480 / 412 : 



16, 19-21, from Station 2886; 



17, from Station 4193; 



18, from Station 2887. 



