124 CEYLON PEARL OYSTER REPORT. 



The skeleton arrangement and spiculation agree closely with those of the last-named 

 variety. The surface brushes of megascleres may or may not be well-developed in 

 different parts of the same specimen. 



In one specimen (R.N. 246) a single finger-shaped process swells up at its free end 

 into an irregular nodular mass, and thus makes an approach to the variety fungoides. 



In R.N. 218 the spirasters are rather longer and the megascleres have better 

 developed heads, and are perhaps usually somewhat stouter than in the type of the 

 variety. 



R.N. 154 (type of variety); 218 (deep water outside pearl banks, Gulf of Manaar) ; 

 246 ; 352 (Ceylon seas). 



Spirastrella vagabunda, var. fungoides, nov. 



The type of this variety is an extremely irregular, massive specimen, growing 

 amongst a quantity of nullipore and other calcareous debris. It is characterised 

 especially by the presence of definite porous areas, either forming irregular depressions 

 on the surface, like large pock-marks, or on the flattened tops of fungoid outgrowths. 

 These are probably inhalant pore-areas, for there are at least two fairly large vents 

 forming the outlets of wide oscular tubes ; one of these vents is situated on a level 

 with the general surface of the sponge, and the other on a low mammiform projection. 

 The structure internally is somewhat cavernous, and the specimen contains a great 

 deal of imbedded foreign matter. The size of the entire mass is about 88 millims. by 

 47 millims. by 47 millims., but a large proportion of it consists of nullipore, &c. The 

 colour in spirit is pale yellowish-grey. 



The main skeleton is dense and confused ; surface brushes are developed in the 

 pore-areas and, as usual, many at any rate of the spicules in these brushes are much 

 smaller than those of the main skeleton. 



Spicules. (1.) Tylostyli ; usually slightly curved; with stout fusiform shafts, well- 

 developed, oval heads and finely and evenly pointed apices ; size in main skeleton 

 about 0'5 millim. by 0'0167 millim. 



(2.) Spirasters ; mostly long, slender and zig-zag ; occasionally up to as much as 

 0'048 millim. long, but usually much shorter. Rarely more than 0'002 millim. thick, 

 exclusive of spines ; occasionally nearly straight. 



In the possession of the occasionally much elongated spirasters this variety 

 resembles RIDLEY and DENDY'S Spirastrella solida (1) from the Philippine Islands, 

 which should perhaps be regarded merely as another variety of S. vagabunda. 



R.N. 54 (type of variety, Gulf of Manaar) ; 253 (Ceylon seas). 



Spirastrella vagabunda, var. gallensis, uov. 



The larger of the two fragments by which this variety is represented in the 

 collection is an irregularly cylindrical piece, about 52 millims. in length, and varying 

 in diameter from about 10 millims. to about 19 millims. The texture is compact and 



