52 THE VOYAGE OF H.M.S. CHALLENGER. 



Tedania tenuicapitata, RicUey (PI. XI. fig. 5). 



188L Tedania ienmcapitata,TLidlej, "Alert" Coll., Proc. Zool. Soc. Lond., January, p. 124, 



pi. xi. fig. 1. 



This species has already been fully described (loc. cit.), it is, therefore, unnecessary 

 to give much further description. The "Alert" obtained only a single sj^ecimen of the 

 sponge while the Challenger obtained a considerable number. 



The Challenger specimens show plainly that the usual form of the sponge is massive 

 (PI. XI. fig. 5). They also show a very considerable range of variation in the character 

 of the ends of the tylota, which vary from a very elongate, slightly demarcate and acutely 

 pointed form to a short, regularly defined head, rounded terminally ;^ the roughening of 

 the fine rhaphides alluded to in the original description (loc. cit.) was made out in one 

 specimen, but only in a spicule which was not adult. So great is the variation of the 

 diactinal spicules and so nearly do they approximate the spiculation of this form to that of 

 Tedania suctoria, Schmidt,^ that it must be considered doubtful whether it is more than 

 varietaUy distinct from it. As yet, however, the structures described as excretory papillae 

 by Schmidt (loc. cit.), have not been found here, and perhaps may prove distinctive. 



Localities.— Station 308, January 5, 1876; lat. 50° 8' 30" S., long. 74° 41' 0" W.; 

 south-west Patagonia; depth, 175 fathoms; bottom, blue mud. Several specimens. 



Station 311, January 11, 1876; lat. 52° 45° 30" S., long. 73° 46' 0" W.; oS" south- 

 west Patagonia; depth, 245 fathoms; bottom, blue mud; bottom temperature, 46° "0. 

 Several specimens. 



Station 314, January 21, 1876 ; lat. 51° 35' S., long. 65° 39' W.; east of the Strait 

 of Magellan ; depth, 70 fathoms ; bottom, sand ; bottom temperature, 46°-0. One fine 

 specimen (PI. XI. fig. 5). 



Habitat. — Off" the south-west coast of Patagonia ("Alert," Challenger); between 

 Strait of Magellan and Falkland Islands (Challenger). 



Tedania commixta, Ridley and Dendy (PI. XXIII. figs. 9, 9a, 9b, 9c). 



1886. Tedania commixta, Ridley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. 



p. 335. 



Sponge massive, amorphous. Colour in spirit creamy-yellow. Texture soft and 

 compact, with a large admixture of foreign grit. Surface slightly corrugated. Dermal 

 membrane thin but distinct. Oscula small, scattered, with their margins flush with the 

 surface. Pores scattered (?). 



Skeleton. — Consisting of very loose, whisp-like fibres, apparently without any definite 



1 Tlie rounded heads of the tylota were observed only in one of the specimens, and even here a large number 

 of these spicules have the heads pointed. 



2 Spong. Atlant. Gebiet, p. 4.3. 



