192 CEYLON PEARL OYSTER REPORT. 



Phakellia ceylonensis, n. sp. Plate VIII., fig. 3 ; Plate XIII., fig. 5. 



The single specimen (Plate VIII., fig. 3) is shortly stipitate, erect, thinly flahellate 

 and very proliferous. The branching and anastomosing vertical lamellae of which it 

 is composed all terminate at about the same level in thin, sinuous margins. The 

 lamellae are scarcely 3 millims. in thickness and have a tendency to become perforated 

 by larger and smaller apertures. The two surfaces of the lamella are not distinguishable ; 

 each is finely conulose (granular) and minutely and slightly hispid. Vents not 

 recognisable. Texture tough and resilient ; colour (in spirit) greyish-brown. Total 

 height only about 41 millims., but with a maximum breadth of about 90 millims. 



The skeleton is dense, composed of plumose columns radiating upwards and outwards 

 into the small surface conuli, and merging internally into an irregular but fairly dense 

 reticulation of spicules. There is a large development of very pale-coloured spongin. 



Spicules. (1.) Styli ; slightly curved or bent, evenly rounded off at the base, 

 usually very gradually and finely pointed at the apex ; of two principal sizes, but 

 very variable : (.) Comparatively short and stout (Plate XIII. , fig. 5, a), say about 

 - 2 millim. by 0'008 millim. (/>.) Long and slender (Plate XIII., fig. 5, b), say about 

 0*44 millim. by 0'005 millim. 



(2.) Oxea (Plate XIII., fig. 5, c, (/, e) ; subject to much the same variations in size 

 as the styli, and variously ended. 



This species is nearly related to Carter's Phakellia jiabellata from Australia {vide 

 Dendy, 10), but for the present at any rate it may be regarded as specifically 

 distinct. 



R.N. 34 (Gulf of Manaar). 



Phakellia crassistylifera, n. sp. Plate XIII., fig. 6. 



The single specimen is a small, irregular, proliferously lamellar and slightly 

 clathrous sponge, without recognisable point of attachment. The surface is granular 

 and minutely hispid, and there are no visible vents. Texture hard, tough, resilient. 

 Colour (in spirit) pale wax-yellow. Height (?) 31 millims. ; greatest breadth about 

 19 millims. ; thickness of lamellae variable, say about 2 millims. 



The skeleton is a very dense, close and irregular reticulation of very stout fibre, 

 composed of a large quantity of almost colourless spongin, in which numerous usually 

 stout styli are more or less completely embedded. The primary fibres are stouter 

 than the secondaries, and may have a somewhat plumose character ; but the whole 

 reticulation is so confused, and the spongin, though very abundant, so pale in colour, 

 that at first sight the entire skeleton looks like a dense, irregular network of thickly 

 scattered styli. 



Spicules. Styli (Plate XIII. , fig. 6); usually stout and comparatively short and 

 more or less curved ; broadly rounded off at the base, which is not narrowed, and 

 usually sharply and gradually pointed at the apex ; but the apex is occasionally 

 bluntly rounded off, so that the spicule becomes strongylote with unequal ends. Size 



