REPORT ON THE MONAXONIDA. Ill 



the backwardly projecting process is greater than in the Kerguelen form. JMr. H. J. 

 Carter ^ has given a very good description of this spicule in Desmacidon [Homceodictya) 

 palmata, with two excellent figures, the correctness of which was most satisfactorily 

 verified by reference to the Bowerbank collection in the British Museum ; it appears to 

 us, however, that the lateral fimbrise of the shaft are usually broader than he has repre- 

 sented them, and the spicule thus makes a still closer approach to that of Desmacidon 

 (Homoeodictya) kerguelenensis than might be judged from his figure. 

 Locality. — Royal Sound, Kerguelen, 25 fathoms. Two specimens. 



Desmacidon {Homceodictya) grandis, Ridley and Dendy (PI. XXII.; PL XXIX. 

 figs. 7, 7a). 



1886. Homceodictya grandis, Ridley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. 



p. 347. 



Sponge (PI. XXII. fig. 1) compressed, lamelliform ; presumably of erect growth. 

 The single specimen in the collection consists of a large, very broad, very much flattened 

 lamella, at one end proliferating into compressed, digitate branches, at the other con- 

 sisting of a simple, flat expansion with incipiently lobate margin. One side of the 

 frond bears very numerous, steUately arranged oscula, placed at very regular intervals 

 from one another ; these form a very prominent feature of the sponge ; they are entirely 

 absent from the other side (cf. PI. XXII. figs, la, Ih). The specimen is of rather irregular 

 shape and has been broken ofi" along its lower margin, so that we cannot tell how 

 far it extended in a vertical direction ; in its present condition it is much broader than 

 it is high, the greatest breadth being about 275 mm. (the lower margin, however, is 

 only about 162 mm. long) and the greatest height about 150 mm. The thickness 

 at the broader end of the piece is about 6 mm. and at the narrower end about 2"5 mm. 

 Colour ia spirit greyish-yellow. Texture firm, tough, fibrous, resilient. Surface on 

 both sides very fairly even, but minutely conulose and very minutely hispid ; conuli most 

 prominent towards and on the free margin ; very harsh to the touch. Dermal membrane 

 thin, transparent, delicate, stretched between the conuli. Oficula minute, arranged in 

 stellate groups of about four each, on one side only of the frond (PL XXII. fig. lb); 

 each group about 2 mm. in diameter; these groups of oscula are very abundant and 

 arranged at fairly constant intervals of about 6 mm. from one another. Pores not found. 



Skeleton. — Very well developed ; composed of stout, branching, Axinella-Yike spiculo- 

 fibre, made up of stout oxeote spicules. These spicules have each one end imbedded in 

 the fibre, while the other projects outwards, towards the surface of the sponge, at a 

 slight angle. The fibres trend towards the surface, where they terminate in tufts of 

 oxeote spicules, thus giving rise to the surface conuli. Parallel fibres may in places be 

 connected by loose crossing spicules. 



1 Ann, and Mag. Nat. Hist., ser. 5, vol. x. p. Ill, fig. 1, a and h. 



