EXPLANATION OF PLATE XL 



Fig. I. Suberites aqiiae-didcioris, sp.nov. 



Portion of skeleton supporting subdermal exhalent chan- 

 nels, as seen from above, X75. 



Figs. 2, 2a, 3. Mycale mytilorumy sp. nov. 



2. — Portion of skeleton supporting a subdermal exhalent 

 channel, as seen from above, X 20. 2a. — Terminal 

 part of a single spicule- fibre, X 75. 



3. — Scattered spicule-fibres at periphery of sponge, as 

 seen from above, X 20. w.m. ^= worm-tube. 



Figs. 4, ^a. Mycale madraspatana, sp. nov. 



4. — Portion of skeleton surrounding an osculum, as seen 

 from above, X 20. 4a.— Terminal part of one of 

 the stouter spicule-fibres, X 75. 



Figs. 5, $a. Lissodendoryx balanophilus , sp. nov. 



5. — Superficial spicule-fibres, X 75. 5a. Part of the 

 same preparation, X 225. The part further enlarged 

 in fig. 4a is indicated by a circle in fig. 4. 



