H. B. Kirk. — On New Zealand Sponges. 209 



Oxea : Clavate, generally obtuse at both ends, uneven ; 

 0-37mm. x 0025nim. 



This sponge is closely allied to Haeckel's Ascandra reticu- 

 lum, from which, however, it may easily be distinguished by 

 the character of its oxea. In A. reticulum these are fusiform, 

 even in outline, and pointed at both ends. In L. laxa they 

 are clavate, wavy in outhne, and obtuse at the broader end, 

 generally at both. Dr. Dendy's L. dubia is very like this 

 sponge, but its quadriradiates are occasional and not constant. 



The external appearance of this sponge is that of L. clatJi- 

 rus. 



Leucosolenia depressa, Dendy. (Monograph.) 

 Occurs in the neighbourhood of Wellington. 



Leucosolenia rosea, n. sp. (Plate III.) 



This sponge forms spreading masses, which may attain a 

 diameter of 75mm. The surface is for the most part remark- 

 ably even, but it rises into rounded lobes and ridges, along 

 which the pseudoscula are placed. The pseudoscula are gene- 

 rally oval in shape, and are from 0-6mm. to 8mm. long. 

 Around the margin of each is a pseudoscular membrane, 

 slightly developed, and not rising above the general sur- 

 face of the sponge. The pseudopores are evenly distributed 

 over the whole surface. The pseudoscula open into pseudo- 

 gasters. A colony often contains a large number of these 

 spaces. The canal system is of Dendy's type D. 



When alive the sponge is of a pale-pink or salmon colour, 

 and the colour remains for a long time in dried specimens. 

 Sjncules : — 



Triradiates : The pseudoderm consists mainly of enormous 

 3-rayed spicules, which show an approach to the tripod condi- 

 tion. Their outline is often wavy, and the broadest part of the 

 ray is often at about a third of the distance from the base to 

 the point. The points of the rays are blunt. Length of ray, 

 0-3mm. ; greatest breadth, 007mm. 



Deep triradiates : The 3-radiates of the inner part of 

 the sponge are regular and sharp-pointed ; the rays tapering 

 evenly. 0-2mm. x 0-018mm. 



The triradiates of the wall of the pseudogaster, and espe- 

 cially those around the pseudosculum, often become sagittal, 

 the oral rays being curved, either towards or away from each 

 other, and the basal ray being shortened. In these regions 

 of the sponge occurs a curious 2-rayed spicule, the third 

 ray having failed to appear, or, having appeared, to develope. 

 Fig. h shows a spicule in which the third ray is incipient. 



Quadriradiates : These are generally rather smaller than 

 the 3-radiates, and the main rays are a little less sharp. The 

 14 



