REPORT ON THE MONAXONIDA. 127 



about 0'42 by 0"0063 mm., dermal ; (2) smooth styli (PI. XIX. figs. 5, 5'), varying much iu 

 size, up to about 2'0 by 0'02.5 mm.; slightly curved aud sharply aud gradually pointed at 

 the apex. Although styli of this size are abundant it is more common to find them much 

 shorter and stouter, measuring about 0'77 by 0'034 mm. The styli make up the 

 main skeleton. Besides these two forms there is a third large spicule which may be 

 mentioned here, although it is probable that from its peculiar form it should be placed 

 rather in the category of microsclera than that of megasclera {vide infra), only its great 

 size argues against this view. It is a very long and very slender oxeote spicule (PI. XIX. 

 fig. 5a'""), sharply pointed at each end, and commonly with a single rather sharp bend in 

 the centre ; size up to about 2"0 by O'Ol mm. These spicules are abundantly scattered 

 throughout the sponge and sometimes occur in bundles ; their occurrence in the dermal 

 membrane has already been referred to. (6) Microsclera ; ( 1 ) very minute, palmate isochelae, 

 about 0"0065 mm. long, scarce; (2) large, stout toxa (PI. XIX. figs. 5a, bh, &c.), measuring 

 about 0'35 by 0*0063 mm. This is about the average size, but there is very considerable 

 variation in this respect, and indeed it is not difiicult to pick out a connecting series 

 between these toxa and the long oxea above mentioned. Such a series is represented 

 on PI. XIX. figs. 5a-5a'"". 



This species is very well marked, and may be readily recognised both by its external 

 appearance and its spiculation. AU the spicules, except the minute isochela, which is 

 unusually small, are of exceptionally large size. The toxa are probably the largest known 

 examples of their kind. Some of them were found still enveloped by the mother-cell, 

 as shown on PI. XIX. fig. 56. The most interesting feature of the species is, however, 

 the manner in which the toxa appear to develop into oxea. 



Localities. — Christmas Harbour, Kerguelen, 70 fathoms. One specimen (the t}^e, 

 from which our description is taken). 



Off Marion Island, between 50 and 75 fathoms. One specimen. 



Ainphilectus dnnectens, Eidley and Dendy (PI. XIX. figs. 4, 4o). 



1886. Amphiledus annedens, Ridley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. 



p. 351. 



Sponge massive, lobate, represented only by a single fragment, 25 mm. long by 

 about 13 mm. bi-oad. Colour in spirit pale, greyish-yellow. Texture very soft and 

 spongy. Surface uneven, rugose, hispid in places (perhaps owing to artificial causes). 

 Dermal membrane distinct, thin and transparent. Oscula small and scattered. 



Skeleton. — {a) Dermal; consisting of tylota loosely scattered through the dermal 

 membrane and also arranged in tufts beneath it. (6) Main; a very loose and irregular 

 reticulation of large styli, in which no distinct fibre is discernible. 



Spicules. — («) Megasclera; of two kinds — (l) very large, stout, smooth, usually slightly 



