580 



Transactions 



Clathriodendron rubrum n. sp. Fig. 6, and Plate XXVlI, fig. 1. 



External Characters : Sponge erect, branching freely, the branches 

 spreading widely. Branching begins close to the basal disc, and here the 

 branches are thick and in section roundish or oval ; above they become 

 flattened and expanded, the ultimate branchings being digitate processes 

 on the margins of these palmate portions. Surface unbroken by conuli ; 

 no oscula observable in the dry state. Height of largest specimen, 9-5 cm. 

 Colour of dried specimen reddish-brown, becoming dark red on immersion 



Fig. 6. — Clathriodendron rubrum. 



1. Section at right angles to surface. 2. Oxeote. 3. Stylus. 4. Tylostyli. 5. Bases of 

 tylostyli. fi. Filiform tylostyli. 7. Spined styli. 8. Doubtful microscleres. 



in water. The colouring-matter is in the sponge-flesh, and dissolves out 

 readily ; it appears to be due to associated Algae. Skeleton tough, and 

 harsh to the touch, becoming soft when wetted. 



Skeleton reticulated ; spongin abundant ; primary fibres generally 

 radiating, and somewhat uneven. The secondary fibres form with them 

 meshes that are oval or polygonal, or often rectangular, the rectangular 

 shape most observable in the younger parts of the sponge. Primary fibres 

 cored more or less abundantl}' with smooth slender styli and tylostyli, 



