274 DISCOVERY REPORTS 



Remarks. The holotype consists of two fragments, the one a small portion of a 

 cylindrical branch, and the other a cylindrical branch, 2 cm. in diameter, which bi- 

 furcates at one end into two short branches rounded at the ends. The second specimen 

 is in fact almost identical in appearance with the specimen figured by Kirkpatrick (1908, 

 pi. xvii, fig. i) under Gellius riidis, Topsent. 



Hemigellius pachyderma, sp.n., diff"ers from H. rudis (Topsent) mainly in the size of 

 the spicules, in the absence of sigmata, and in the dense aggregation of spicules im- 

 mediately beneath the dermis. But all these characters are comparative, and it may 

 possibly be shown eventually that the two species are synonymous. In any case, the 

 dermal palisade may certainly be accepted as the homologue of the paniculate surface 

 brushes in H. rudis. 



Genus Adocia, Gray 



Adocia carduus (Ridley and Dendy). 



Gellius carduus, Ridley and Dendy, 1886, p. 333 ; G. laevis, id., loc. cit., p. 333 ; G. carduus, id., 

 1887, p. 39, pi. viii, fig. 3, pi. xiii, fig. 7; G. carduus, var. magellanica, id., loc. cit., p. 40, 

 pi. xiii, fig. 6; G. laevis, id., loc. cit., p. 40, pi. xiii, fig. 8. 



Occurrence. St. 160: near Shag Rocks, 177 m.; St. 177: South Shetlands, 1080 m. ; St. WS 81 : 

 Falkland Islands, 81-82 m.; St. WS 83 : Falkland Islands, 137-129 m. 



Remarks. Judging from the observations made on the new material, there is no 

 possibility of distinguishing between Gellius carduus and its variety magellanica and 

 G. laevis. The external form of the new specimens resembles, in each case, that of 

 G. carduus, var. magellanica. The megascleres, which vary from oxea to incipient 

 strongyla, measure from 0-3 to 0-45 mm. long, and the sigmata vary from 0-015 to 

 0-02 mm. chord. 



Distribution. Crozet Island; Prince Edward Island; Marion Island; Magellan 

 Straits ; mouth of the Rio de la Plata. 



Adocia glacialis (Ridley and Dendy). 



Gellius glacialis, Ridley and Dendy, 1886, p. 333; id., 1887, p. 41, pi. viii, fig. u, pi. xiii, figs. 

 I, 15, 19; G. glacialis, var. nivea, id., loc. cit., p. 42, pi. viii, fig. 8, pi. xiii, figs. 4, 12; Kirk- 

 patrick, 1908, p. 49, pi. xvii, fig. 4; Burton, 1929, p. 397. 



Occurrence. St. 140: South Georgia, 122-136 m.; St. 190: Palmer Archipelago, 93-130111.; 

 St. WS 82: Falkland Islands, 140-144 m.; St. WS 83 : Falkland Islands, 137-129 m. 



Remarks. Comparison of the present specimens with those in the Swedish Antarctic 

 Collection and with the types of both the species and its variety has shown that the 

 var. nivea cannot be maintained. The question will be dealt with fully in my forth- 

 coming report on the sponges of the Swedish Antarctic Expedition. 



The sigmata in one of the present specimens resemble those of A. {Gellius) flagellata 

 (Ridley and Dendy). 



Distribution. Agulhas Bank ; Prince Edward Isle ; Victoria Land. 



