PLATE 17. 



Geodia media Bowerbank. 

 Figs. 1-22. 



1-3. — Group of strongylosphacrasters of a massive specimen; magnified ISOO ; u. v. phot. Zeiss, q. 

 monochr. 1.7, q. oc. 10: 



I, focused high; 2, focused intermediate; 3. focused low. 



4, 5. — Group of euasters of a massive specimen; magnified GOO; u. v. phot. Zeiss, q. monochr. 2.5, q. 

 oc. 5: 



4, focused higher; 5, focused lower; 



a, small strongylosphacrasters; b, large oxyaster. 

 6. — Group of euasters of a massive specimen; magnified 300; u. v. phot. Zeiss, q. monochr. G, q. oc. 7: 



a, small strongylosphacrasters; b, large oxyaster. 

 7-12. — Mesoclades and mesoclade-derivates; magnified 200; phot. Zeiss, apochr. 8, compcns. oc. 6: 



7, a mesoclade-derivate with knob- like cladome-rudiuient of a massive specimen; 



8, 9, mesorthomonaenes of a massive specimen ; 

 10, mesoplagiomonaene of a massive specimen; 



II, 12, mesopromonacnes of the digitate specimen. 



13, 14. — Small strongylosphacrasters of a massive specimen; magnified 1800; u. v. phot. Zeiss, q. 

 monochr. 1.7, q. oc. 10. 



15. — Euasters of the digitate specimen; magnified 300; phot. Zeiss, hom. imm. apochr. 2: 



a, small strongylosphaeraster; b, large oxyaster. 



16, 17. — A small strongylosphaeraster of a massive specimen; magnified 1800; u. v. phot. Zeiss, q. 



monochr. 1.7, q. oc. 10: 

 16, focused higher; 17, focused lower. 

 18, 19. — Groups of euasters from a centrifugal spicule-preparation of the digitate specimen; magnified 

 300: 



18, phot. Zeiss, hom. imm. apochr. 2; 



19, phot. Zeiss apochr. 4, compens. oc. 6; 



a, small strongylosphacrasters; b, large oxyasters. 



20. — Part of a large oxyaster of a massive specimen; magnified 1800; u. v. phot. Zeiss, q. monochr. 



1.7, q. oc. 10. 



21, 22. — Parts of a radial section through the cortex of a massive specimen; magnified 20); phot. Zeiss, 



apochr. 8, compens. oc. G: 



21, part passing through the distal portion of the cortex; 



22, part passing through the proximal portion of the cortex; 



a, outer surface; b, more or less radially disposed small dennal styles just below the outer 

 surface; c, sterrasters; d, small dermal styles lying paratangentially at the proximal 

 limit of the cortex ; e, inner fibrous layer of the cortex with few scattered sterrasters. 



Geodia variospiculosa Thiele. 



Figs. 23-26, 34-40, 49. — var. intermedia Lendenfeld. 

 Figs. 27-33, 41-48, 50. — var. micraster Lendenfeld. 



23-26. — Anatriaene-cladomes of var. iw<er?7iedia; magnified 40; phot. Zeiss, apochr. 16. 

 27. — An anatriaene-cladome of var. micraster; magnified 75; phot. Zeiss, apochr. 16, compens. oc. G. 

 28-31. — Anatriaene-cladomcs of var. micraster; magnifieil 40; phot. Zeiss, apochr. 16: 

 28-30, regular anatriaene-cladomes; 



31, an irregular anatriaene-cladome with one clade shortened and rounded at the end. 

 32. — Cladome of a somewhat irregular mesoprotriaene of var. wucrasfer; magnified 75; phot. Zeiss, 

 apochr. 16, compens. oc. 6. 



