the ^Challenger ' Monaxonida. 341 



Esperio^sis challengeri (Ridley) *. 



The best idea of the external form of this sponge will be 

 obtained from the figure referred to *. Erect, stipitate, giving 

 oif brandies on one side only, each of which terminates in a 

 concave lamellar expansion. Length up to about 8 inches, with 

 six or seven lamella3. Light yellow. Stem densely fibrous, 

 lamellae rather fragile and soft. Pores very abundant on 

 concave surface of lamelljB. Vents small, abundant on 

 convex surface of lamellae. Spicules : — (1) curved acuates, 

 gradually sharp-pointed, size about '35 by •01.26 millim. ; 

 (2) palmate equianchorates, length "031 millim. This species 

 possesses the most remarkable and beautiful external form of 

 all known Monaxonid sponges. 



Localities. Station 196, east of Celebes Island, 825 fath., 

 abundant ; Station 2 14, south of Philippines, 500 fath. (var. 

 meangensis^ fragments only). 



Esperiopsis profunda, n. sp. 



Stipitate, with narrow tubular head ; height up to about 

 4 inches. Light yellowish grey. Soft and spongy. Hispid. 

 Skeleton very loose in the head. Spicules: — (1) acuate to 

 spinulate, gradually sharp-pointed, size 1*4 by '0157 millim.; 

 (2) large palmate equianchorates, length up to *09 millim., 

 but more commonly about "05 millim. 



Locality. Station 147, Southern Ocean, 1600 fath. 



Esperiopsis anomala, n. sp. 



Digitate ; irregularly ramose. Greyish yellow or grey. 

 Soft and compressible, but elastic and very fibrous, Ghalina- 

 like. Dermal membrane delicate and transparent. Skeleton : — 

 (a) dermal, loose tufts of spicules ; (h) main, rectangular, 

 composed of stout spiculo-fibre with much spongin and few 

 spicules. Spicules: — (1) long slender acuates, tending to 

 subspinulate, sharp-pointed, size about "25 by "005 millim., 

 but commonly longer and slenderer ; (2) very rare, very 

 minute, very slender equianchorates, length about '01 millim. 



Locality. Honolulu, 16-20 fath. 



Esperiopsis (?) pulchella, n. sp. 



Very small, thin patches of a blackish colour, incrusting a 

 Myxilla. Pores in definite areas or sieves, eacli area about 



* Amphilectus challengeri, Ridley, Narr. of Cruise of H.M.S. 'Chal- 

 lenger,' vol. i. pt. 2, p. 570, tig. 187. 



Ann. & Mag. N. Hist. Ser, 5. Vol. xviii. 24 



