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



Gelliodes licheniforrnis, Lamarck, sp. (PL XII. fig. 3 ; PL XLVII. figs. 1, la). 



1813. Spongia liclienifonnis, pars, Lamarck, Ann. Mus. Hist. Nat. Paris, vol. xx. p. 371. 

 1836. Spongia licheniforrnis, Lamarck, Hist. Anim. sans Vert., t. ii. p. 543. 



To this species we refer a single, encrusting, very lichen-like specimen from Station 

 "135 (?) 60 fathoms." The Challenger sjiecimen difi"ers from the type (as evidenced by 

 a dry specimen in the British Museum, in the series of Lamarckian sponges), in 

 having slightly larger sigmata and a more slender fibre ; in its present condition the 

 surface is also more even, but no doubt this is in part due to the fact that the specimen is 

 preserved in spirit. As so little is known of the species we may add a few details derived 

 from an examination of the Challenger specimen. 



Sponge (PL XII. fig. 3) sessile, encrusting. Colour in spirit light yeUowish-brown. 

 Texture (in spirit) soft, spongy, very fibrous. Surface uneven. Dermal meonbrane verj- 

 thin and transparent. Pores small, scattered. Oscula f 



Skeleton. — A not very regular reticulation of strongly developed, very distinctly 

 lamellated, horny fibre cored by oxeote spicules, and of oxeote spicules united together 

 by more or less ho]"ny substance (spongin). In addition to the main skeleton thus 

 constituted there is a very well-developed and beautiful dermal reticulation (PL XLVII. 

 figs. 1, la) of spiculo-fibre, consisting of a unispicular network of oxeote spicules with a 

 very large proportion of spongin ; backed up behind by a network of much stouter 

 spiculo-fibre, with very few spicules and still more spongin. 



Spicules. — (a) Megasclera ; of one kind only, viz., straight, smooth oxea, measuring 

 about 0'23 by 0'0096 mm. (b) Microsclera ; of one kind only, viz., smooth, slender 

 sigmata, usually measuring about 0*032 mm. in length, very rarely up to about 0"09 

 mm ; thickness about 0*0012 mm. 



The Challenger specimen might readily be mistaken for a young form of Gelliodes 

 pocidum, nobis, but this idea is precluded by the difi"erent character of the dermal skeleton. 

 There is no doubt that Lamarck's Spongia licheniforrnis includes more than one species, 

 both as shown by the specimens in the British Museum and by his own statement (loc. 

 cit.) : — "Habite dans difierentes mers, et ofire beaucoup de varietes." Our specimen 

 agrees sufficiently closely with that in the British Museum to be ranked in the 

 same species with it, but regarding Lamarck's other varieties we are not able to speak 

 with certainty. 



Gelliodes poculum, Eidley and Dendy (PL X.). 



1880. Gelliodes poculum, Eidley and Dendy, Ann. and ]\Iag. Nat. Hist., ser. 5, vol. xviii. p. 334. 



Sponge (PL X.) consisting of a thin, spreading lamina, which, in the case of the 

 Challenger example, grows over a large, massive Tetractinellid sponge ; from this 



