84 THE VOYAGE OF H.M.S. CHALLENGEE. 



This sponge is interesting on account of the great depth (1600 fathoms) from which it 

 was obtained, and with this must again be associated the presence of a definite external 

 form. It is distinguished from other species of the genus by its very long megasclera 

 and by the external form. 



Locality. — Station 147, December, 30, 1873; lat. 46° 16' S., long. 4S° 27' E.; 

 between Prince Edward Island and Crozet Islands, Southern Ocean ; depth, 1600 fathoms ; 

 bottom, Diatom ooze ; bottom temperature, 34° -2. Two specimens, in bad condition. 



Esperiopsis anomala, Ridley and Dendy. 



1886. Esperiopsis anomala, Eidley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, voL xviii. 



p. 341. 



Sponge digitate, irregularly ramose ; branches subcylindrical, varying in diameter. 

 One of the two specimens in the collection measures nearly 125 mm. in length but only 

 about 6 mm. in average diameter. The second is about 50 mm. long and 8 broad, 

 being somewhat compressed and giving ofi" a few short, stumjay branches. Colour in 

 spirit light greyish-yellow to dark grey. Texture very soft and compressible, but elastic, 

 fibrous, and fairly tough. Surface uneven. Dermal membrane thin, delicate, trans- 

 parent, rather loosely attached to the underlying tissues. Oscula (?). Pores, very 

 abundant rounded openings through the thin dermal membrane, of various sizes. 



Skelet07i. — (a) Dermal; represented only by sparse, radiating brushes of spicules 

 with outwardly projecting points, {h) Main; a rectangularly meshed reticulation of 

 stout spiculo-fibre with primary and secondary lines distinct. Fibre containing a very 

 large amount of spongin and few spicules. 



Sjncules. — {a) Megasclera; long but very slender styli, sometimes tending to become 

 tylostylote, sharply pointed; size about 0-25 by 0'005 mm. {h) Microsclera; very 

 minute, very slender isochelse, very scarce, found in the dermal membrane, seen only in 

 side view ; length about O'Ol mm. Owing to their great slenderness these spicules are 

 very diflicult to make out; they give one the impression of being on the verge of dis- 

 appearance. ■ They become visible after prolonged soaking in Canada balsam. 



The most remarkable feature about this sponge is the very strong development of 

 spongin, which gives it quite a Chalinine appearance. It forms a very good instance of 

 the manner in which horny fibre may be developed in any genus. 



Locality. — Honolulu, 16 to 20 fathoms. Two pieces. 



Esperiopsis pulchella, Ridley and Dendy (PL XIX. figs. 9, 9', 9a, 96, 9c, 9d ; PI. 

 XXX. fig. 3, e). 



1886. Esperiopsis (?) pulchella, Eidley and Dendy, Ann. and Mag. Kat., ser. 5, vol. xviii. p. 341. 



Under the above name we propose to describe a very small, encrusting sponge from 



Station 192. The sponge occurs in very small and excessively thin patches of a blackish 



