PLATE 47. 



Geodia acanthtylastra Lendenfeld. 

 Figures 1-8. 



1, 2. — Large acanthtylaster; magnified 1800; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10: 



1, focused higher; 2, focused lower. 

 3. — Group of asters from a centrifugal spicule-preparation; magnified 1800; u. v. phot. Zeiss, q 

 monochr. 1.7, q. oc. 10: 



a, small strongylosphaeraster; b, large acanthtylasters. 

 4-6. — Acanthtylasters; magnified 1800; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 



7. — Group of asters from a centrifugal spicule-preparation: magnified 1800; u. v. photi Zeiss, q. mon 



ochr. 1.7, q. oc. 10: 



a, small strongylosphaeraster; b, large acanthtylaster. 



8. — Large acanthtylaster; magnified 1800: u. v. phot. Zeiss, q. monochr. 1.7, q oc. 10. 



Geodia lophotriaena Lendenfeld. 

 Figures 9-36. 



9-21. — Side views of lophotriaenes and plagiotriaenes; magnified 50; phot. Zeiss, apochr. 16, compens 

 oc. 2: 



9-12, 14, 19, lophotriaenes with more or less irregular cladomes and long simple, pointed rhabdomes 

 13, 15, 16, 18, dichotriaenes with regular cladomes and long pointed rhabdomes: 

 17, plagiotriaene; 



20, lophotriaene with bifurcate rhabdome; 



21, plagiotriaene with short enwl and terminally rounded rhabdome. 



22. — The sponge seen from above; magnified 3.5; phot. Zeiss, anastig. 167. 



23. — Radial section through the superficial part of the sponge; magnified 100; phot. Zeiss, apochr. 16, 



compens. oc. 6: 



a, dermal membrane; b, sterraster-armour; c, choanosome. 



24. — Radial section through the superficial part of the sponge; magnified 10: phot. Zeiss, planar 50: 



a, cortex; b, choanosome. 

 25-33. — Cladomes of dicho- and other lophotriaenes seen from below (the rhabdome is directed verti- 

 cally upwards); magnified 50; phot. Zeiss, apochr. 16, compens. oc. 2: 

 25-29, cladomes of dichotriaenes; 



30, 33, cladomes of lophotriaenes with one trifurcate and two bifurcate clades; 



31, cladomes of a lophotriaene with one bifurcate, one trifurcate and one quaterfurcate clade; 



32, cladome of a lophotriaene with one quaterfurcate and two trifurcate clades. 



34. — Mesoj)rotriaene; magnified 50; phot. Zeiss, apochr. 16, compens. oc. 2. 



35, 36. — Cladomes of anatriaenes; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 



