256 DISCOVERY REPORTS 



It is pedunculate, without root-tuft, and still bears at its base a portion of the black rock 

 on which it was growing. 



Fig. I. Rossella 7iuda, Topsent. Base 

 of a specimen from St. 123, with basal 

 tuft and an incipient stalk, x f . 





Fig. 2. Rossella nuda, Topsent. A second 

 specimen showing the same features, but 

 with the stalk placed laterally. 



The next three specimens are dried. The first is cylindrical, 75 cm. high by 30 cm. in 

 diameter, with only a scanty root-tuft as in the ^-form. The lower two-thirds of the 

 sponge is covered with numerous well-developed papillae without projecting pleuralia, 

 but on the upper third the papillae are scarce. They are often as much as 5 cm. high and 

 may be bifid, or even trifid. In this sponge, then, are combined the characters of the 

 b-, c- and ^-forms. The second specimen, 22 cm. high and 9 cm. in diameter, is com- 

 pletely covered with small papillae devoid of projecting pleuralia, and with the basalia 

 segregated into sparse bundles as in the ^-form. The basalia are few in number and 

 feebly developed, recalling the condition found in the e- and /-forms. The chief interest 

 of this specimen is, however, the fact that the sponge was probably attached directly by 

 its base, and did not rely on its basal tuft although it is slightly developed, since this is 

 continued downwards as a short stalk (Fig. i). But, judging by the appearance of the 

 base, and by the presence of numerous small fragments of black rock embedded in the 

 outer tissues, it was not attached to a rock but buried in the mud. The third specimen is 

 very similar to the foregoing, is 30 cm. high and 17 cm. in diameter, completely covered 

 with papillae and bears sparse bundles of basalia. This sponge appears to have been 

 attached by a laterally placed basal plate (Fig. 2). 



Distribution. South Georgia; Graham Land; Victoria Land; Wilhelm Land. 



Rossella racovitzae, Topsent. 



(For synonymy see Burton, 1929, p. 407.) 



Occurrefice. St. 160: near Shag Rocks, 177 m.; St. 190: Palmer Archipelago, 93-130 m.; 

 St. WS 225: Falkland Islands, 162-161 m.; St. WS 248: Falkland Islands, 210-242 m. 



