263 



Fig. 20. — Hircinia arbuscula, x ^ ; 20a, section, x ^ ; 206, 

 cortex at junction of poral and imperforate surface, x 4. 



Fig. 21. — Psaimnopemma inordinaUim, x ^; 21a, ditto., poral 

 area, x 5. 



Plate VI. 



Fig. I. — Placospongia carinata : a, subtylostyle, x 80 ; b, stron- 

 gyle, X 80 ; c, oxea, x 80 ; d, sterrasters, x 80, with 

 sketches showing development of ends of actines; e, 

 somal chiaster, x 730 ; /, pycnaster, x 730. 



Fig. 2. — Latrunculia nataleusis : a, strongyle, x 80 ; b, tornote, 

 X 80 ; c, c', curved and straight styles, x 80 ; d, d', 

 discaster, side and end view, x 730 ; e, choanosomal 

 discaster, x 730. 



Fig. 3. — Kalastrella vasifotuiis : a, strongyle, x 80 ; 6, oxea, 

 X 80 ; c, style, x 80 ; d, thick straight style, very 

 rare, x 80 ; e, small tyle or subtylostyle, x 420 ; /, 

 euasters, x 730. 



Fig. 4. — Kalastrella vasiformis, var. minor. : a, oxea, x 80 ; b, 

 style, x 80 ; c, small tyle, x 420 ; other spicules as in 

 Fig. 3- 



Fig. 5. — Coppatias bacidifer : a, a', oxeas, x 80 ; b, micro- 

 strongyles, x 730. 



Fig. 6. — Tetliya magna : a, strongyloxea, x 80 ; 6, cortical 

 spheraster, x 730 ; c, somal chiaster, x 730 ; d, choano- 

 somal aster, x 730. 



Fig. 7. — Trachya niida : a, vertical section, x 5 ; 6, oxea, x 80. 



Fig. 8. — Axinyssa tethyoides : a, branching skeleton fibres, x 5 ; 

 /), oxea, X 80. 



Fig. 9. — Phakellia microxephora : a, vermicular strongyles, x 80 ; 

 b, style, X 80 ; c, oxea, x 80 ; d, microxea, x 80. 



Fig. 10. — Tragosia infiuidibulifot mis, var. natalensis : a, ectosomal 

 skeleton network, x 5 ; 6, style, x 80 ; c, oxea, x 80 ; 

 d, e, style and oxea from Johnston's type, x 80. 



Fig. II. — Syringella gorgonioides : a, transverse section of a small 

 twig, X 2 ; 6, style, x 80. 



Fig. 12. — Hymeiiiacidon caliculaium : styles, x 80. 



Fig. 13. — H. caliculaium, var. oscnlatum : styles, x 80. 



