SPONGES.--HALLMANN. 



(2). Form (/)). (PI. xxxiii., fig. 2, and figs. 49, 49a). 



The branches are sub-cylindrical or but slightly compressed, 

 5 to 7 mm. in diameter, and lie in a single plane. The main 

 branches divide dichotomously and occasionally anatomose ; 

 the secondary branches often extend across the interval be- 

 tween adjoining main branches and effect a connection between 

 them. The sponge is accordingly flabellate, and consists of a 

 reticulation of branches; it measures 120 mm. in height and 

 130 mm. in breadth. Wart-like prominences of irregular size 

 and shape are scattered over the surface. As in the typical 

 form, there is no appearance of a dermal 

 membrane, and the colour in alcohol is 

 pale yellowish grey ; owing to the smaller 

 size of the principal styli, however, the 

 surface is much less distinctly hispid. 



r\ 



Fig. 48- C /ra;/- 

 sicns (form b). a 

 Principal styles, b 

 Auxiliary tylostyle. 



Mesascleres. — 



Fig. 48fl — Clathria transiens 

 (form b"). a Accessory styles, 

 b Chelse. c Toxa. 



(i.) The principal styli vary in length from no to 43011, 

 but very seldom exceed 320 >* ; their maximum dia- 

 meter is 13 f(. 



