227 



the slope, presents turts of spicules (oxea and protria^nes) which 

 form a fringe round the circular edge. The surface is smooth and 

 even, excepting where fissures have formed, in one of which the 

 excurrent canals opens. The colour is greenish grey. CJn 

 section the nucleus, whence the skeletal fibres radiate, is seen to 

 be on the vertical axis passing from base to apex^ and at the 

 junction of the middle and lower third- 



The spiculation is identical with that of the type specimen. 



The under surface of the new specimen is smooth and 

 free from foreign bodies^ but the same region in the type is en^ 

 crusted with sand particles. 



The remarkable shape of the type specimen evidently results 

 from contraction due to drying. 



Locality. — False Bay, S. Africa, 22 fathoms; the type specimen 

 came from Port Elizabeth. 



Family Pachastrellidae. 



Genus Pachastrella, Schmidt. 

 Pachastrella caliculata, sp. n. 

 Plates II and III, fig. 4. 



Sponge caliculate with thick rounded rim and hard thick walls. 

 Outer poral surface smooth, here and there nodulated; inner 

 oscular surface finely cribriform over nearly the whole area, 

 oscules about .75 mm. Colour pale buff. 



Skeleton mainly composed of densely-packed calthrops of vari- 

 ous sizes, with bundles of oxea arranged at right angles to the 

 sponge surfaces ; microstrongyles forming a dense surface layer 

 and distributed through the body of the sponge. 



Spicules. Megascleres. — Oxea (Fig. 4a) 4800 X 45 /<# straight 

 or curved, with sharp or rounded points. 



Calthrops of many sizes (Fig- 4b-f), the largest with thick rays, 

 each 1085 X 240 /«, ends pointed, but often obtuse and contorted; 

 some with a fourth ray longer than the other three. 



Microscleres. — Microstrongyles (Fig- 4g) 12 X 5-5 /"' prolate- 

 ellipsoid, with granulated surface. 



Microrhabds (Fig. 4h) 25 X 3 /', curved, closely and finely 

 spined, not centro-tylote. 



Amphiasters (Fig. 4k) 11 X n I-', including spines, with 4-5 

 truncated rays with granular surface. 



Locality.— Durnford Point, Natal, N.W. f W., distant 12 miles ; 

 depth 90 fathoms. Bottom — broken shells. 



The solitary specimen, which is shaped somewhat like a sitz- 

 bath without the bottom, has been cut off sharp from its attach- 

 ment. 



The greatest height is 10 cm; the diameter of the cut base 10 

 cm.; the thickness of the wall at the cut base 3 cm., and of the 

 edge .75 cm. 



