486 A MONOGRAPH OF THE AUSTRALIAN SPONGES, 



The specimens of Euspongia irregularis silicata are lobate or 

 massive, but never digitate, sometimes bulbous and spherical. 

 The lobes are slightly flattened and irregular, large and not 

 numerous. This variety is small, the largest lobate specimen 

 measures 120 x 90 mm. The lobes may attain a height of 20 mm., 

 and a similar width, they measure about 8 mm. in thickness. 



Occasionally no massive central part at all is developed, and 

 then we meet with different forms. These are lobate, but already 

 approach towards the digitate forms. They are, however, always 

 compressed, so that the lobate character is retained, however much 

 they may resemble digitate forms. 



The specimens of Eusjoongia irregularis httea are massive and 

 irregular without any processes at all. The largest measure to 

 150 mm. in diametei-. 



The specimens of Eiispongta irregularis tenuis possess a very 

 irregular shape with rounded processes. The extensive vestibule 

 spaces render this variety similar to Hippospongia. Some of the 

 specimens of this variety attain a large size, measuring 200 mm, 

 in the largest diameter, generally, howevei', they are much smaller. 



The specimens of Euspongia irregalaris Jacksonia are decidedly 

 digitate. These sponges have an irregular shape and attain a size 

 150 mm. in their greatest diameter. The digitate processes which 

 grow out from the central irregular mass all tend upwards, 

 they are found particularly well developed on the upper side 

 of the sponge. Most of them are cylindrical and rounded at 

 the top. Possessing a circular transverse section these are truly 

 digitate. A few, however, also appear lobate and irregular. They 

 attain a length of 30 mm. and are generally 8 mm. thick. Those 

 which grow out from the side of the sponge are curved, so that 

 their terminal parts are vertical. 



