214 CEYLON PEARL OYSTER REPORT. 



ground-substance between them is finely granular. I have not been able to make out 

 the nature of their openings. The usual cylindrical cords of elongated fibre-cells are 

 present, and there is a collenchymatous ectosome. There appears also to be a thin 

 cuticle similar to that of various species of Hippospongia. 



As regards skeletal characters this species agrees closely with Lendenfeld's very 

 comprehensive Euspongia irregularis, but the external appearance is so characteristic 

 that it seems to deserve a distinct specific name. 



li.N. 311 ; 331) (Yard Cove, Trincomalee, shallow water). 



Hippospongia, Schulze. 



Spongiida; of clathrous structure, but otherwise resembling Euspongia, except that 

 the skeleton fibre may be much coarser and the whole sponge harder. 

 Except in its harder and more incompressible character, I cannot see that 

 Lendenfeld's genus Hyatella differs from Schulze's Hippospongia, yet Lendenfeld 

 himself describes a Hippospongia dura which is, perhaps, as hard as any Hyatella. 



Hippospongia intestinalis (Lamarck). 



1813, Spongia intestinalis, Lamarck (73); 1877, Spongelia velata, Hyatt (69); 1884, 

 Hippospongia intestinalis, Ridley (16) ; 1889, Hyatella intestinalis, Lendenfeld (66). 



This species is represented in the collection by several specimens of elongated 

 tubular form, very intestinal in appearance and of a light brown colour, with their 

 walls perforated here and there at irregular intervals, and the surface slightly 

 conulose. The tubes may branch and anastomose, but are for the most part well 

 separated from one another and usually about 10 millims. in diameter, but variable. 

 The characteristic surface reticulation of slender horny fibre is very well developed, 

 and the surface appears to be covered by a remarkable continuous but separable 

 cuticle, which possibly has some connection with the dermal skeleton, but I have not 

 been able to elucidate its true nature. The main skeleton is very irregular and 

 composed of mostly stout amber-coloured horny fibre. Primary fibres cored with 

 foreign bodies are visible here and there. 



The flagellate chambers are small (about 0'03 millim. in diameter) and approxi- 

 mately spherical, and the ground-substance between them is finely granular. The 

 special exhalant canaliculi, if present, are short. Stout bands of elongated fibres, 

 presumably muscular and mostly longitudinal in direction, are developed as in other 

 Spongidse, and there may be a good deal of collenchyma around some of the larger 

 canals. 



The species has been recorded from the Mediterranean, Zanzibar, the Mascarene 

 Islands, and the Amirante Group (66), and from Porto Rico (29). 



R.N. 65 (Gulf of Manaar); 83 (deep water off Galle and onwards up West 

 Coast) ; 337 (Ceylon seas). 



