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



arms. (Very similar to the ellipsoid Spongurus cylindrimis, Monogi-. d. Radiol., p. 465, Taf. xxvii. 

 fig. 1, but differs in the compressed lenticular (not ellipsoidal) form of the central disk; the 

 transverse section of the arm is elliptical, not circular.) 



Dimensions. — Eadius of the arms O'l, breadth 0"04. 



Hahitat. — Pacific, central area. Station 270, depth 2925 fathoms. 



3. Spongolena cypselura, n. sp. 



Arms nearly triangular, not longer than broad, about half as large as the eUiptical central disk, 

 at the broader distal end with two very large, widely divergent lateral spines, and between them 

 several smaller, like the tail of a swallow. Surface thorny. 



Diinensions. — Eadius of the arms 0-2, distal breadth (without spines) OlS, basal breadth 0-07. 



Halitat. — Pacific, central area, Station 272, depth 2600 fatlioms. 



Genus 261. Sjwngobrachium,^ Haeckel, 1881, Prodromus, p. 461. 



Definition. — S p o u g o d i s c i d a with two opposite spongy arms on the margin of 

 the disk, connected by a spongy patagium of different texture. 



The genus Spongohrachiiim differs from the foregoing only in the loose spongy 

 patagium, which envelops both opposite spongy arms. It corresponds to Amjjhymenium 

 among the Porodiscida and to Amphiactura among the Coccodiscida. 



1. Spongohrachium ellipticum, Haeckel. 



SponrjoeijcUa elh'ptiea, Haeckel, 1862, Monogr. d. Radiol., p. 470, Taf. xxviii. fig. 2. 

 Sponijodiscus elliptkui, Haeckel, 1860, Monatsber. d. k. preuss. AkaJ. d. Wiss. Berlin, p. 844:. 



Arms nearly square, scarcely as long and broad as the radius of the circular central disk, at 

 the broader distal end truncated. Patagium complete, enveloping the whole disk with the arms, 

 and forming a larger elliptical disk of looser framework. (In my Monograph, 1862, loc. cit., I 

 had not distinguished the opposite darker arms, opposite in the longer a.xis of the elliptical disk,, 

 from the enveloping looser framework of the patagium. In larger specimens of the Challenger 

 collection this distinction is very evident.) 



Dimensions — Eadius of the arms 0"12, breadth 0*05 ; major axis of the elliptical patagium 0-24, 

 minor 016. 



Habitat — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface. 



2. Spongohrachium lanceolatum, n. sp. 



Arms club-.shaped, twice as long as broad, at the distal end pointed, five times as long as the 

 radius of the circular central disk. Patagium complete, enveloping the whole disk with the arms, 

 ^ Spongohrachium = S'pongj shell with two arms ; a'lroyyos, fi^axluu. 



