302 DISCOVERY REPORTS 



echinating acanthostyli, persistently overlooked by previous authors, may occur (of. 

 Table, p. 297) ; (2) the variation in the occurrence and distribution of the anisochelae 

 and bipocilla. 



Distribution. Kerguelen; Cape of Good Hope; Tristan da Cunha; South America 

 (Patagonia and Chile); Galapagos Islands; Canada (Pacific and Atlantic coasts). 



Section TEDANIEAE 



Genus Tedania, Gray 



(For further notes on the Antarctic species of this genus see p. 342.) 



Tedania tenuicapitata, Ridley (Fig. 25/). 



T. tefitiicapitata, Ridley, 1881, p. 124, pi. xi, fig. i. 



Occurrence. St. WS 73 : Falkland Islands, 121 m.; St. WS76: Falkland Islands, 205-207 m.; 

 St. WS 79: Falkland Islands, 131-132 m.; St. WS 83: Falkland Islands, 137-129 m.; St. WS 88: 

 Falkland Islands, 96-12701.; St. WS99: Falkland Islands, 251-225 m.; St. WS239: Falkland 

 Islands, 196-193 m.; St. WS 243 : Falkland Islands, 144-141 m.; St. WS246: Falkland Islands, 

 267-208 m.; St. WS 248: Falkland Islands, 210-242 m.; St. WS 250: Falkland Islands, 251-313 m. 



Remarks. The holotype of T. tenuicapitata, Ridley is a small sub-pyramidal sponge, 

 from Chile, probably incomplete, and its external characters are thus somewhat obscure. 

 Its surface is even, minutely punctate, with several oscules, 2 mm. in diameter, on the 

 upper margin. The spicules are: styli 0-38 by 0-013 mm., tornota 0-28 by o-oo6 mm., 

 and onychaeta o-o8-o-i05 mm. and 0-32 mm. respectively. The several specimens as- 

 signed to this species by Ridley and Dendy (1887) vary from small and irregularly 

 massive to flabellate, and form in themselves a well-graded series of transitions from the 

 holotype to the large flabellate specimen illustrated by these authors {loc. cit., pi. xi, 

 fig. 5). The surface may be almost smooth or thrown into meandrine folds, to an extent 

 far greater than suggested by Ridley and Dendy 's illustration ; and there are all stages 

 between these two extremes. Thus, in one specimen the surface is smooth and even, but 

 beneath the dermis, and visible through it, the underlying tissues have a meandrine 

 formation such as is seen in Artemisina diaiiae, Topsent (1908, pi. iii, fig. 4). In extreme 

 cases, the surface is folded like that of Tedania oxeata, Topsent (1917, pi. iv, fig. 14). 

 The spicules in the Challenger specimens measure: styli o-35-o-49 by o-oo7-o-oi4 mm., 

 tornota 0-28-0-3 by o-oo4-o-oo6 mm., and onychaeta 0'07-o-28 mm., with no apparent 

 division into groups of diff'erent sizes. 



The present specimens vary in form and appearance to a slightly greater extent than 

 the Challenger specimens, but are still massive to flabellate, with all intermediate forms 

 between these two, and the surface is even, with the underlying tissues thrown into 

 meandrine folds of varying size, or itself thrown into coarse and conspicuous meandrine 

 folds. The spicules measure: styli o-35-o-49 by o-oi-o-oi8 mm., tornota o-i8-o-39 by 

 0-004-0-0II mm., onychaeta, very variable, not always clearly differentiated into groups 

 of different sizes, but on the whole they may be represented by the measurements 0-07- 

 o-i8 mm. and o-28-o-43 mm. 



Distribution. Chile. 



