SPONGES. 321 



spicula project; but a longitudinal section shows the 

 spicula built up one on another in many courses, so 

 nearly symmetrical that hexagonal canals are formed, 

 whose axes run transversely to the axis of the sponge ; 

 i.e., horizontally. There is very little fleshy or gelatin- 

 ous matter. 1 



Again we see a showy species, 2 making soft, spongy 

 patches of an orange or red-lead colour, an inch or 

 more in diameter, rising into ridges a quarter of an inch 

 high, and forming low peaks, whose apices are perforate. 

 Its substance contains simple needles, long, nearly or 

 quite straight, pointed at one end ; these are found in 

 great numbers in close array, the points mostly project- 

 ing from the surface. Some of them are twice as thick 

 as others. 



Now we notice another peculiar form : 3 creeping, 

 worm-like masses of orange-yellow or buff hue, soft 

 and spongy in texture, which throw up one or more 

 free, erect processes, irregularly curved, an inch or 

 more long, and about one- eighth thick on an average, 



1 Leuconia Gossei (Bowerbank MS.). Dr. Bowerbank, to whom I have 

 communicated this species, thinks that it may have been confounded by 

 former observers with the preceding. " The broad specific difference 

 between them is that L. nivea has very large triradiate spicula at its 

 surface, and L. Gossei has not, but has in lieu of them very large acerate 

 ones at right angles to the surface." (Bowerb. in Hit.) 



2 Hymeniacidon caruncula. 



3 Hymeniacidon albescens. 



