PLATE 42. 



Geodia ovis Lendenfbld. 

 Figures 1-40. 



1. — Radial section through the superficial part of the sponge; magnified 30; phot. Zeiss, planar 20: 



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



2. — Radial section through the superficial part of the basal part of the sponge and the spicule-fur; 



magnified 10; phot. Zeiss, planar 50: 



a, surface of the sponge; b, c, d, freely protruding spicules of the spicule-fur: b, large 

 amphioxes; c, small anaclades; d, orthotriaenes. 



3. — Group of spicules from a centrifugal spicule-preparation; magnified 200; phot. Zeiss, apochr. 8, 



compens. oc. 6: 



a, minute dermal amphioxes; b, minute dermal anaclade; c, asters. 

 4-7. — Minute dermal amphioxes; magnified 200; phot. Zeiss, apochr. 8, compens. oc. 6. 



8. — Radial section through the .superficial part of the sponge; magnified 20; phot. Zeiss, planar 20: 



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



9. — Radial section through the dermal layer of the cortex; magnified 100; phot. Zeiss, apochr. 16; 



compens. oc. 6: 



a, dermal membrane ; b, sterraster-armour; c, tufts of minute dermal rhabds. 



10. 11. — Cladomes of minute dermal anaclades; magnified 1800; u. v. phot. Zeiss, q. monochr. 1.7, 



q. oc. 10. 



12-17. — Asters and groups of such from centrifugal spicule-prepa rations; magnified 300; phot. Zeiss, 

 apochr. 4, compens. oc. 6: 



a, large thick-rayed oxyasters; b, large thin-rayed oxyasters; c, small strongylasters. 

 18, 19. — Groups of oxyasters with medium rays from a centrifugal spicule-preparation; magnified 330; 



phot. Zei.ss, apochr. 4, compens. oc. 6. 

 20-22. — Groups of asters from a centrifugal spicule-preparation; magnified 540; u. v. phot. Zeiss, q. 

 monochr. 6, q. oc.lO: 



a, large thick-rayed oxyasters; b, large thin-rayed oxyasters; c, small strongylasters. 

 23, 24. — Groups of spicules from' a centrifugal spicule-preparation; magnified 330: phot. Zeiss, apochr. 

 4, compens. oc. 6: 



a, minute dermal rhabd ; b, minute dermal anaclades; c, asters. 

 25. — Small anatriaene; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 

 26-40. — Cladomes of anatriaenes; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6. 



