8P0NGIIDA. 619 



spicular columns radiating horizontally from the axial skeleton, but 

 much disguised by crossing spicules, sometimes united into secondary 

 fibres. Axial skeleten — the longitudinal linos strong, but in basal 

 parts of sponge confused by close aggregation ; the axis of the lla- 

 bellate parts is composed, on the contrary, of a dense mass of horizon- 

 tally arranged spiculos, from which the short dermal tufts project 

 so as to appear on the surface of the sponge. Bases of spicules of 

 radiating lines and much of the entire axial spicular columns 

 enveloped in a tough transparent substance, amber-yellow in dry, 

 salmon-colour in spirit-specimens. 



Spicules : — (1) Acuate, smooth, curved slightly but rather abruptly 

 at from one third to one half tho distance from the base ; tapering 

 gradually from about middle, more rapidly from about three fourths 

 of length, to sharp points, and sometimes slightly towards base; 

 base rather squarely rounded ; size -55 by -032 to -045 millim. 

 (forms chief part of the axial and radial columns and tho secondary 

 fibres). (2) Acuate, smooth, straight or slightly curved, tapering 

 gradually to fine points from about one fourth of the length from 

 the apex; base well rounded ; size -5 to 1-8 by -015 to -02 millim. 

 (sparingly, in company with no. 1, in most parts ; especially, attached 

 to bases of radiating columns, and projecting outwards in a direction 

 parallel to them). 



I lab. Providence Island, Mascarene group, 18 and 19 fms. ; bottom 

 coral. 



Two small specimens in spirit, one large dried dredged specimen, 

 and two medium-sized beach- worn specimens represent the species ; 

 the largest measures 120 millim. (5 inches) in both greatest height 

 and lateral extent ; the stem is 20 millim. in greatest lateral by 

 8 millim. in greatest antero-posterior diameter. The species has 

 much of the external appearance of Spongia carduus, Lamarck, of 

 the Paris Museum, the spiculation of which, however, refers it to 

 another genus. It differs from all the species described by Schmidt 

 from European and W. -Indian seas in the absence of an acerato 

 spicule; in the great stoutness of the main acerate it approaches 

 A. mastojyhom of that author, from Florida. In general habit it 

 resembles Acanthella rather than Awinella, but wants the long 

 undulating cylindrical spicule hitherto found in species of that 

 genus ; it appears doubtful whether the existence of such species 

 as this should not induce us to unite the two genera. I have been 

 uuable to identify it with any described species ; the large stout 

 acerate appears to be the most distinctive characteristic. 



LEUCOPHLCEUS. 



Carter, Ann. 8f Mag. N. H. 1883, xii. p. 323. 



In its affinities this genus appears to be Axinellid ; it is dis- 

 tinguished from Axinella, s. str., by its loose yielding texture, the 

 skeleton- fibres being loosely united, but containing a dense keratose 



