BY E. F. KALLMANN. 



351 



illustrates a more reticulately branched example of the species. 

 The latter specimen, which consists of somewhat flattened, 

 anastomosing branches forming a reticulate mass, approxi- 

 mates to Lendenf eld's description of Tedania laxa, though not 

 so closely as do two other specimens which occur among the 

 type-specimens of that species ; and which, on account of their 

 somewhat irregularly arranged skeleton, I at first thought to 

 be specifically different from the rest. I mention this because, 

 whereas Lendenfeld states that Stylotella digitata is intensely 

 orange-coloured, and Tedania tenuis'pina bright orange-yellow 

 in the living state, he states, of Tedania laxa, that "the colour 

 of the living sponge is bright brick-red"; and it is possible, 

 therefore, that two varieties of S. agm'nuita occur, which differ 

 in colour, and perhaps, to a slight extent also, in other 

 respects. 



The main skeleton (Pl.xx., fig. 2) exhibits great variability 

 iti its precise mode of arangement, but always consists (i.) of 

 longitudinally-running spicule-fibres, which are unconnected 

 by cross-fibres, and from the most peripherally situated of 

 which, short branches arise that pass outwards to the surface ; 

 and (ii.) of spicules which, though they are sometimes abun- 

 dant, for the most part lie scattered singly. Diversity in the 

 conformation of the skeleton results through variation in 

 number of the scattered spicules, and through differences in 

 stoutness of the main fibres, and in their distance apart. For 

 descriptive purposes, four chief types of arrangement are dis- 

 tinguishable ; but apparently all gradations between these 

 occur, and different types may be found in different parts of 

 one and the same specimen. (i.). The fibres are closely 

 arranged, running parallel to one another at a distance apart, 

 which may be even less than their own diameter; and scat- 

 tered spicules are scarce or absent : this condition, which is 

 uncommon, appears most usually to be met with in slender 

 cylindrical branches. (ii.).The fibres are more widely separated, 

 and scattered spicules occur in greater or less abundance, 

 usually crossing one another in all directions so as to produce. 



