25. — Part of a radial section through the distal part of the choanosome of var. micraster; magnified 200; 



phot. Zeiss, apochr. 8, compens. oc. 6: 



a, medium-sized oxyaster; b, smaller oxyasters. 



26. — Radial section through the superficial part of var. -micraster; magnified 20; phot. Zeiss, planar 



20: 



a, sterraster-armour ; b, a chone; c, small dermal styles and anaclades protruding beyond the 

 surface; d, choanosome; e, small dermal styles and anaclades in the subcortical layer. 



27. — Part of a radial section of the proximal portion of the choanosome of var. intermedia; magnified 



200; phot. Zeiss, apochr. 8, compens. oc. 6: 

 a, large oxyasters; b, smaller oxyasters. 



