EEPORT ON THE MONAXONIDA. 235 



m.'immiform processes ; towards the summit of the sponge many of these processes are 

 hirger than elsewhere, measuring about 6 mm. in height ; these are conical and have 

 each a distinct oscular opening at the top. Much more abundant are the smaller processes, 

 which occur abundantly all over the upper surface of the sponge, excepting where they 

 are replaced by the larger ones ; they are very short, cylindrical, and abiaiptly truncated 

 at the top. The larger processes are undoubtedly cloacal tubes, and we were at first 

 inclined to think that the small ones might be the same in a state of retraction, but we 

 have now very strong evidence in favour of regarding them as raised pore-areas. Canals 

 in the body of the sponge lead up to both kinds ; the smaller ones, however, appear to 

 the naked eye to be almost all closed at the top. This description also applies fairly 

 to the two specimens from Station 320. The larger of the two is more globular and 

 smaller than the Kerguelen sponge ; the difference between the large and small papilli- 

 form processes is not so well marked ; but the sponge is in poor condition for making 

 out anatomical details ; it is even impossible to decide whether there was one or more 

 large oscula at the summit ; that there was at least one is certain. The small processes 

 are more conical in form, and, though plentiful, not nearly so abundant as in the 

 Kerguelen sponge. Colour in spirit (of the specimens from Station 320) yellowish-grey. 

 The specimen from Kerguelen is of a deep chocolate brown colour throughout ; but as all 

 the specimens in the bottle with it, and also the parchment label, were found to be 

 stained of the same colour, we cannot be certain to which sponge the colour may lie 

 proper. Texture fairly compact, but spongy throughout, with tough, parchment-like 

 dermal layer easily separable from the deeper tissues. In the Kerguelen specimen the 

 cortex is a good deal thicker than in the specimens from Station 320, and may be 

 described as tough and leathery. Surface smooth between the mammiform processes, 

 but rather harsh to the touch. Oscula on the tops of mammiform processes. Pores; 

 narrow perforations through the flat tops of the smaller mammiform projections, leading 

 into large inhalent canals. 



Skeleton.. — There is a dermal crust composed of a single layer of the characteristic 

 Latrunculia " chess-man " spicules (discastra), vertically placed and with outwardly 

 directed, elongated apices. Below these the skeleton is very loose and irregular, com- 

 posed of abundant smooth stylote spicules disposed without any definite order. Imme- 

 diately below the surface these spicules tend to be vertically arranged, but this layer 

 passes very soon into a much denser but utterly irregular reticulation, and below this 

 again, forming the main mass of the skeleton, is a loose, irregular reticulation of the 

 same spicules, often forming incipient fibres but with no distinguishable primary and 

 secondary lines. The discastra also occur scattered promiscuously throughout the sponge. 

 In the Kerguelen specimen the dermal layer of discastra is immediately backed up 

 by a thick, dense layer of closely interwoven stylote spicules. It thus ajipears thnt 

 there is great irregularity in the arrangement of the main skeleton. 



