210 CEYLON PEARL OYSTER REPOET. 



R.N. 72 (outside pearl banks, Gulf of Manaar) ; 279 (deep water off Galle and 

 onwards up West Coast of Ceylon). 



Psammopeinma, MARSHALL. 



Spongeliidse in which the skeleton is composed of densely aggregated sand-grains 

 which are more or less connected together by spongin. 



Psammopemma crassum (CARTER), var. clathrata, nov. 



1885, Holopsamma crassa, CARTER (18) ; 1889, Psammopemma crassum, LENDENFELD (66). 



The specimens differ from the types as described by Mr. CARTER in their clathrous 

 form and in the absence of large conspicuous vents. They are extremely irregular 

 and friable, and densely charged with coarse sand, over which a distinct pellucid 

 dermal membrane, free from sand, is frequently stretched. The surface is very 

 uneven, sometimes ribbed and sometimes conulose ; the texture incompressible but 

 fragile, and the colour (in spirit) pale brown. 



The sand grains are not arranged in distinct fibres, but in ill-defined bands forming 

 an irregular reticulation. They are connected at the points of contact by a very 

 small quantity of spongin cement. 



The flagellate chambers are large (about 0'08 millim. in longer diameter) and sac- 

 shaped, and open direct into the exhalant canals by wide mouths. The ground 

 substance between them is clear and transparent and very sparsely developed, except 

 in the neighbourhood of the larger canals, which are surrounded by an abundant 

 gelatinous collenchyma, with numerous stellate or fibrous connective-tissue cells. 



The types of the species came from Australia, and LENDENFELD also records it from 

 New Zealand. 



K.N. 64 (type of variety, Gulf of Manaar) ; 330 (Ceylon seas). 



FAMILY: SPONGIID^. 



Euceratosa with a reticulate horny skeleton and with small, more or less spherical 

 flagellate chambers, commonly provided with special narrow exhalant canaliculi. 

 The ground-substance between the chambers is compact and densely charged 

 with fine granules. 



Cacospongia, SCHMIDT. 



SpongiidaB with a very wide-meshed skeleton network, and with distinctly lamellated 

 horny fibres which are usually of a brown colour and of very variable diameter. 



Cacospongia scalaris, SCHMIDT. 



1862, Cacospongia scalaris, SCHMIDT (47) ; 1879, Cacospongia scalaris, SCHULZE (72) ; 

 1889, Stelospongia scalaris, LENDENFELD (66). 



There are several rather small specimens in the collection which agree closely with 



