TETKAXOXIDA. 33 



they pass upwards; the separate fibres of the main lnmdles altout 80 /m thick. The 

 main bundles joined at right-angles by secondary fibres, 1-3 spicules thick. Spongin 

 not perceptible. Ectosomal skeleton formed of circles of strongyles, the spicules isolated 

 or in fan-like wisps, arranged partly vertically, partly tangeutially round the pure areas : 

 the vertical spicules usually isolated, and the tangential ones in wisps. On drying tin- 

 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, 402 X 13 /", 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 G'5 /u, smooth, occasionally slightly swollen at each* 

 end. 



Microsclerea. 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 flabellate 

 fronds are obviously formed of fused tubular digitations, as can be seen from the 

 oscules along the upper edge and from the faintly indicated longitudinal grooves down 

 the sides. The walls of the oscular canals are smooth and lined with numerous 

 orifices of exhalant canals, about 3 mm. in diameter. The arrangement of the pores 

 in circular areas each surrounded by a zone of ectosomal spicules is not common in 

 Tedania ; it occurs in the second new species described below, and something of the 

 kind is found in Tcdnn'ui tenuicapitata Ridley (15a. p. 124), from the Straits of 

 Magellan. In the present species this feature is so well marked as to give the surface 

 a pock-marked appearance. 



The rhaphides, usually so characteristic of TrJiuiln, have entirely disappeared ; 

 but the loss of microsclcres is of such frequent occurrence that it has not seemed 

 necessary to create a new genus or subgenus to include such forms ; though, perhaps, 

 the more or less definite arrangement of the ectosomal spicules might, in the present 

 instance, necessitate such a course. 



The specimen wa.s dredged near Winter Quarters, 10 fms. 



TEDANIA COULMANI. 



(Plate XXL, fig. 2. Plate XXV., lig. 2a-b\) 

 I'.inT. Ti'ilanlti coiiliiiiini Kirkpiitnrk (10a. p. -Si>). 



Description. The single specimen is in the form of a finger-like IVagmeni 

 5*5 cm. long and 17 cm. in its greatest thiekness. The colour is dirty gray, and the 

 consistence soft. The surface shows the same circular pure-sieve areas as in 7' r<iri<>l<i. 

 Along one side of the sponge the surface has been turn away, exposing an exhalant 

 canal running along the length of the specimen, but the terminal oscule has apparently 

 been torn away. 



2 E 2 



