HTI'POSPOI!irGIA. 1 41 



that of the vestibular lacunse Bmooth. The grooves on the surface of the 

 skeleton are very irregular, 2-4 millim. wide. Dry skeletons are hard and 

 elastic, dark dirty brown in colour. 



The skeleton consists of smooth main fibres 0-058 millim. thick, which are 

 cored witb abundant small sand-grains (0-009 millim.), and between which a 

 network of connecting- fibres 0-03 millim. thick is spread out, the irregularly 

 polygonal meshes of which average 0-2 millim. in width. 



Geographical Disteibution. — East coast of Australia : Port Jackson 

 Wollongong, N. S. W. (Lendenfeld). 



Hippospongia galea, Lendenfeld. 



Euspongia galea, E. v. Lendenfeld, "A Monograph of the Australian Sponges. 

 — Part VI. The Genus Euspongia" Proceedings of the Linuean Society 

 of New South Wales, vol. x. p. 543 (1885). 



Cup-shaped sponges, attaining a height of 250 millim. and a breadth of 260 

 millim. The distal portion of the cup is cylindrical, the margin continuous 

 and circular. Just below it the cup-wall is thin, but it increases rapidly as 

 we approach the base, where it attains a thickness of 100 millim. The 

 massive body is pervaded by extensive vestibular canals. The outer surface 

 is irregular, covered with deep longitudinal grooves at varying intervals, 

 whilst the inner surface appears more even. Both surfaces are perforated by 

 numerous holes, 1-10 millim. wide, which are situated in close proximity to 

 each other. 



The dry skeleton is of a bright amber colour, hard and elastic. 

 The skeleton consists of main fibres 0-04-0-07 millim. thick, which are slightly 

 knotty and cored with more or less longitudinally disposed fragments of foreign 

 siliceous spicules. The connecting-fibres are much branched and continually 

 anastomose to form a very fine network with polygonal meshes. Stouter and 

 more slender connecting-fibres can be distinguished. The stouter ones form a 

 wide-meshed network, in the meshes of which the slender fibi-es expand. 

 The former, which measure on an average 0-027 millim. in thickness, can be 

 regarded as primary connecting-fibres, and the latter, which are only 0-008 

 millim. thick, as secondary connecting-fibres. Both are free from foreign 

 bodies. 



Geographical Distribution. — South coast of Austraha : Tasmania {British 

 Museum Coll.) East coast of Australia {Ramsay). 



