34 R. KIRKPATRICK. 



Skeleton. Rings of spicules partly vertical, partly tangential, isolated or in 

 tufts, surround the pore areas. 



The choanosomal skeleton is formed of primary longitudinal fibres about 120 /j. 

 thick, joined by secondary fibres one spicule in length and 2-3 in thickness, joining the 

 former at right angles. 



Spicules. Megascleres. The choanosomal acanthostyles, 475 X 18 /*, curved, 

 smooth, or with sparse spines, usually on the upper and lower thirds of the 

 length. 



Dermal ectosomal tornotes, 319 x 12 '5 /*, smooth, straight, fusiform, larger at 

 one end than the other. Under a high power each end shows a rounded shoulder 

 prolonged into a mucronate spine. Microscleres absent. 



The present species resembles T. variolosa in having the circular pore areas, 

 and in the absence of rhaphides, but differs widely in the character of the dermal 

 tornotes. Both species differ from all other species of Tedania in having no 

 microscleres. The nearest species to the present one are Tedania tenuicapitata Ridley, 

 from the Straits of Magellan, and Trachytedania spinata Ridley, from the same locality ; 

 both of these have rhaphides, and neither have the circular pore areas, though in 

 T. tenuicapitata there is a tendency to a radial arrangement of bundles of dermal 

 spicules. The spination of the acanthostyles recalls a similar character in Trachyte- 

 dania spinata. 



The specimen was dredged off Coulman Island in 100 fms. 



II. GROUP MYCALEAE, LUNDBECK. 



ARTEMISINA APOLLINIS. 



(Plate XX., figs. 4, 4a-c.) 



1887. Amphilectus apollinis Ridley and Dendy (15. p. 124). 

 1894. Artemisina apollinis Topsent (24. p. 13). 

 1905. Artemisina apollinis Lundbeck (13. p. 114). 

 1907. Artemisina apollinis Topsent (81. p. 70). 



The single example is a massive cake-shaped specimen 8x8 cm. in area, and 

 4 5 cm. in its greatest thickness. The colour is dirty white in alcohol. One of the 

 surfaces is smooth and opaque, and probably the sponge lay free on the bottom on this 

 side. There is a large oval oscule (l'5x '5 cm.) on one of the edges, and several 

 much smaller oscules on the upper surface. The sizes, in fi, of the spicules are : 

 curved styles 600 x 16; straight styles 400 X 6; chelae 13; toxa 300 (or less) x 3. 

 The flagellated chambers, 29 X 23 M in diameter, are eurypylous. An interesting 

 feature, not occurring in the type specimen from Kerguelen Island, is the presence of 

 small fusiform villous processes (XX. 4a) on the surface, especially round the margins 

 of the oscules ; similar villi, but larger, are found in the nearly related sponge 

 named Esperiopsis edicardii, var. americana R. and D. The finding of this sponge 

 in the Antarctic adds another to the list of bipolar species. 



