458 Mr. R. Kirkpatrlclc on a new 



from deptlis of 140 and 154 fathoms, about 70 miles north of 

 Lion's Head, Soutli Africa. 



Family Rossellidae. 



Subfamily AcAyTHASciy^, F. E. Schulze, [I] p. 348. 



Genus Rhabdocalyptus, F. E. Schulze, [2] p. 15.5. 



Rhahdocalyptus lophodigifafus, sp. n. (PI. VIII.) 



Sponge in form of a thick-walled subglobiilar cup, from the 

 base of which proceed solid dio;itate processes provided with 

 tufts of basalia, forming? in the fully grown condition a dense 

 root-tuft ; tufts of basalia also originating from the general 

 basal surface of the sponge. Outer surface provided with 

 small conical papilla?, from which bundles of pentact pleuralia 

 project radially, the paratangential rays of the spicules forming 

 a veil about 15 centim. from the surface. Orifice subcircular, 

 with thin naked edge. Cavity of cup shallow, with smooth 

 walls, and with very large openings at the lower part leading 

 into wide cavernous efferent canals. 



Skeleton. — Fureyichymalia long diacts, wholly smooth or 

 roughened towards the ends, the more slender in bundles and 

 the thicker isolated, those in the digitate basal processes 

 being stouter and more spinous than those in the body-wall. 



Autoderinalia finely spined diacts, 600-1000 /aX 10-15 fi, 

 often with two or four central knobs. 



Hypodermalia oxypentacts with the paratangential rays 

 paratropal, the two external often forming an angle of 180°, 

 more or less curved, smooth, or finely shagreened, or sha- 

 greened and provided with irregularly distributed thorns, 

 sharp in young, but blunt and occasionally branched in older 

 spicules. 



Basalia long oxypentacts with short orthotropal or para- 

 tropal paratangentials, slightly curved, shagreened, and occa- 

 sionally with small spines ; the outer end of the proximal 

 ray often shagreened. Diact basalia apparently absent. 



Autogastralia spinous diacrs similar to the autodermalia. 



Microsderes. — 1. Discoctasters : a, large kind, 130-160 /* 

 in diameter, knobbed centrum 12-14 /u,, principal rays 18 /*, 

 terminal rays 48-60 /x. 



Principal rays appearing to split up by fission at different 

 levels into 6—8 terminal rays, the latter being slightly curved 

 and divergent, and provided with fine spines pointing back- 

 wards and a 4- to 8-toothed disk. 



6, small kind, 60 /a in diameter, with secondary rays more 

 divergent than in the large discoctasters. 



