SPONGES. 215 



Hippospongia clathrata (CARTER) Plate XIV., fig. 2. 



1881, Hircinia clathrata, CARTER (5); 1887, Hircinia clathrata, DEXDY (2); 1889, Hircinia 

 clathrata, DKXDY (3) ; 1889, Hyatella clathrata, LKNDEXFELD (66). 



There is a single specimen of this well-characterised sponge in the collection. 

 LENDENFELD (66) has added particulars as to .the canal-system to our previous 

 knowledge. The sponge contains no filaments, hut the bands or cords of fibrous 

 tissue in the choanosome, so characteristic of many other Spongidse, are very well 

 developed. The species was recorded by CARTER from the Gulf of Manaar and the 

 Red Sea, and it also occurs in Australia (DENDY, LENDENFELD) and on the American 

 coast of the North Atlantic (LENDENFELD). 



The figure represents the characteristic appearance of a spirit specimen, no good 

 illustration of the external form having yet been published. 



RN. 24 (Gulf of Manaar). 



Hippospongia anomala, POLEJAEFF. 



1881, Hippospongia anomala, POLKJAEFF (74) ; 1889, Hippospongia anomala, LENDEXFEI.D (66). 



There is one specimen in the collection which, although of smaller size, agrees very 

 well in nearly all respects with POLEJAEFF'S description and figure of the type 

 specimen from Torres Straits. Our specimen consists of an erect, sub-cylindrical 

 cavernous body, expanding gradually below and giving off two short digitiform 

 processes on one side. The interior, especially in the lower portion, is sub-divided by 

 trabeculse, and the surface is covered over by a thin, parchment-like dermal membrane 

 pierced by numerous larger and smaller circular apertures, especially abundant 

 towards the extremity. These apertures lead into the large vestibular spaces in the 

 interior of the sponge. The end of the main body and those of the two processes 

 taper suddenly to rather sharp apices, and are covered with fairly numerous small 

 conuli, elsewhere the surface is nearly smooth and glabrous and provided with a 

 delicate cuticle, like that of Hippotponjfui intestinalis. POLEJAEFF'S expression 

 " shagreen-like " may refer to the same character. The colour (in spirit) is pale grey, 

 .the texture compressible and very resilient. The height of the specimen is about 

 120 millims. and the maximum diameter at the base about 50 millims. 



The skeleton is a pretty close but irregular polygonal-meshed network of fibres of 

 very uniform diameter, about 0'02 millim. to 0'03 millim. thick, and free from foreign 

 bodies. Occasionally only one observes much stouter primary fibres, composed 

 principally of broken sponge spicules, running towards the surface and sometimes 

 branching. Occasionally also one sees very slender connecting fibres amongst the 

 ordinary ones ; these are probably young. There is no specially differentiated dermal 

 skeleton, but the main skeleton reticulation comes close to the surface. A good many 

 broken spicules are scattered in the dermal membrane. 



The canal system is remarkable for the unusual length of the exhalant canaliculi 

 of the flagellate chambers, reminding one of the similar condition described by 



