of the J^ational Antarctic Expedition. 279 



pi. xi. fig. 7, and pi. xv. fig. 27), from the White Sea ; but, 

 in addition to other differences, the latter species has no 

 isochelse arcuatre. 



Localities. Winter Quarters, 125 fath. ; off Balleney I., 

 254 fath. 



Tedania variolosa^ sp. n. 



Sponge in form of a mass of thick flabellate or digitate 

 fronds arising from a common base ; with circular sphinctrate 

 oscules., each about 1 cm. in diameter, situated at the summits 

 or along the upper edges of the branches, the canals into 

 which tliey lead extending nearly to the base of the branches. 

 General surface of the sponge covered with circular pore- 

 areas each about 4 mm. in diameter, the oval or circular pores 

 being about 90 fi in diameter, and the strands of the poral 

 reticulum about 30 /i in breadth. Colour in spirit pale brown. 

 Consistence soft and fleshy, being easily torn. 



Flagellated chambers, 42 x 35 |tt, oval, aphodal, with 

 aphodus (in a measured example) 13 /x long. 



Skeleton . — Choanosomal skeleton formed of loosely agglo- 

 merated compound, longitudinal, or main bundles about 

 1 mm. in diameter, curving out to the surface as they pass 

 upwards ; the separate fibres of the main bundles about 80 /x 

 thick. The main bundles joined at right angles by secondary 

 fibres 1-3 spicules thick. Spongin not perceptible. Ecto- 

 somal skeleton formed of circles of strongyles, the spicules 

 isolated or in fan-like wisps, arranged partly vertically, 

 partly tangentially, round the pore-areas ; the vertical spicules 

 usually isolated and the tangential ones in wisps. On drying 

 the sponge the edges of the pore-areas stand up sharply, the 

 areas themselves sinking in, giving a pock-marked aspect to 

 the surface. 



Spicules. — Megascleres : choanosomal styles, 402x13 |tt, 

 curved at about one fourth of the length from the round end, 

 smooth, but occasionally with a few spines about the head. 

 Ectosomal strongyles, 261 X 6'5 ix, smooth, occasionally 

 slightly swollen at each end. 



Microscleres none. 



The single specimen is in the form of a squarish mass of 

 thick fleshy flabello-palmate or digitate lobes ; the height is 

 18 cm. and the breadth 13 cm. 



The arrangement of the pores in circular areas each 

 sui-rounded by a zone of ectosomal spicules is not common in 

 Tedania ; it occurs in the second new species described belovv, 

 and something of the kind is found in Tedania tenuicajntata^ 

 Kidley, from the Straits of Magellan. lu the present species 



