K>4 f'HALIKOrSILLA. 



Familia SPONGID^. 



Cornacuspongise with small ciliated chambers under 0*05 

 millim. wide, without proper spicules, never clathriform. 



The Spongidic are allied to the Homorrhaphidse. We may assume that they 

 have been derived from them by the loss of the proper spicules. 



Genus CHALINOPSILLA. 



Ramified Spongidse with digitate branches, with special surface- 

 skeleton and smooth surface ; imitating various species of Chali- 

 ninoe. Supporting-skeleton forming a network with square 

 meshes. Connecting-fibres mostly unbranched. 



This genus was originally established by me under the name Chalinoims. 



Chalinopsilla australis, n. sp. 



Eepent incrusting or branched and reticulating sponges, with large conspi- 

 cuous and protruding circular oscula. Surface-sl-eleton composed of primary 

 and secondary fibres. Supporthig-skeleton with narrow meshes 0-4 millim. 

 wide and main fibres 0-2-0-35 millim. thick. The connecting-fibres are 

 simple and 0-05-0-08 mUlim. thick. The skeleton is entirely free from foreign 

 bodies. The central part of the reticulate variety and the basal part of the 

 incrusting variety are lacunose, in consequence of the great size of the 

 exhalant canals in these parts of the sponge. 



Chalinopsilla australis, var. reticulata, nov. 



Irregular, decumbent, reticulate sponges. The branches are much and 

 irregularly curved, knotty, and of varying thickness ; their transverse section 

 is more or less circular ; they ramify and anastomose with each other very 

 frequently. The termini of the branches are situated at one end of the 

 elongate, horizontally expanded, sponge. The sponge attains a length of 

 100 millim. and more, and rises 20-30 millim. over the base of attachment; 

 it is attached at numerous points throughout the length of the digitate branches, 

 which are 8-15 miUim. thick. The oscula are conspicuous and very numerous 

 on the upper side of the branches, but rare or absent on the lower side ; 

 they are circular, shghtly raised over the surrounding surface, l"5-3 millim. 

 wide and 3-6 millim. apart. The distribution of the oscula is somewhat 

 irregular ; they often congregate in small groups of 5-15, and are, within 

 these groups, very close together. J-he surface is smooth. The sponge is. 



