246 



Axinella(f) paiadoxa, Ridley and Dendy [15, p. 187], a 

 small massively lobate sponge with oxeas for its spicules, would 

 come under Axiiiyssa, which genus, with A. topsentii., Lenden- 

 feld [12, p. 116] includes three species. 



Sigmaxinella (Dendy). 



Sigmaxinella arborea, sp. n. 



Plate v., Fig. 13. Plate VI., Fig. I4a-c. 



Sponge erect, ramose, with long stem and long dichotomous 

 branches, the lower ones compressed, the upper cylindrical. 

 Surface formed by the apices of hispid tufts. Oscules 

 scattered, very small, about i mm. 



Colour (in spirit) pale brown. 



Skeleton formed of a dense axis of reticulating fibres of 

 spongin with megascleres, the tufts, simple or branched, 

 radiating out horizontally from the axis. 



Spicules. Megascleres. — Styles, 800-1150 x 25-37 ^', curved 

 near the upper end, which is attenuated to 17 f. 



Strongyles, 700-870 x 25-30 /*. 



Rhaphide-like oxeas (very rare) 825 x 12.5 /^, straight, slender. 



Microscleres — Rhaphicles solitary or as trichodragmas, 

 slightly fusiform, 70 a* long. 



Sigma 15 M long and i h- thick. 



Localities A, D, G. — East London, 85 fms. ; Cape Vidal, 

 Natal, 80-100 fms., bottom rocky ; and O'Neil Peak, Natal, 

 55 fms., bottom broken shells. 



There are three specimens, the largest being 31 cm. in height 

 and 21 cm. in breadth, the stem being 12 cm. in length and 

 2x1 cm. in diameter. 



The new species is very nenr Sigtiiaxinella aiistraliana, Dendy 

 [7, p. 240] which forms a bushy bunch of short slender 

 branches. The main difference lies in the spiculation ; the 

 styles, for instance, in the Australian species are only 300 x 6 /«, 

 and the raphides only 25 a*. 



Sigmaxinella incrustans, sp. n. 



Sponge forming a pale-brown woolly-looking crust about 

 6 mm. tiiick. 



Skeleton formed of branched plumose columns rising verti- 

 cally from ixise to surface, the latter being covered with an 

 ectosomal layer of microscleres. Spongin present, but not to 

 a great extent. 



Spicules. Megascleres. - Style, 1085 x 33 n, being 31 f at 

 the base, with a gradual cuive in the upper third. 



