BY E. P. KALLMANN". 



78 L 



finely hispid with the points of projecting spicules. The der- 

 mal membrane is thin and closely adherent; the dermal pores 

 could not be discerned. Oscula are apparently absent. In 

 alcohol the colour is yellowish-grey, the texture dense, the consis- 

 tency fairly firm and tough; the branches, however, are lax, not 

 stiff. The original specimen apparently was more rigid, since 

 its consistency has been described as hard and tough. As a re- 

 sult of maceration (by means of caustic potash) a thin super- 

 ficial layer of the sponge, of softer consistence, disappears, and 

 there is left a dense, solid-looking core, the surface of which 

 presents a somewhat bristly appearance due to the stubs of 

 radially-directed, detruncated spicule-strands. 



Skeleton. — The skeleton (PI. xxxvii., fig. 3) presents, in each 

 branch of the sponge, a very dense axial region, or core, occu- 

 pying from about one-third to somewhat above one-half the dia- 

 meter of the branch, and composed chiefly of longitudinally- 

 running, closely apposed, sponginous fibres containing each a 

 fairly compact core of moderately short and slender, slightly 

 curved styli. These main fibres are connected, partly by very 

 short and inconspicuous, aspicular to paucispicular, transverse 

 fibres, and partly also by occasional inosculation with one an- 

 other, to form an indistinct reticulation with elongated, very 

 narrow meshes. Also participating in the formation of the 

 axial skeleton are rather numerous slender straight styli, similar 

 in every way to those composing the dermal spicule-bundles. 

 These auxiliary, extra-fibral styli are directed parallelly to the 

 main fibres, and are aggregated for the most part into bundles 

 and strands. In the youngest portions of the sponge, towards 

 the extremities of the branches, spongin is developed only to an 

 extremely slight extent (PI. xxxvii., fig. 2) ; but in the older 

 portions it increases in quantity till finally the interstices of the 

 axial skeleton are entirely obliterated. The outermost fibres of 

 the axial skeleton,- however, remain always comparatively scan- 

 tily provided with ensheathing spongin; and the pattern of the 

 peripheral zone of the axial skeleton is generally somewhat irre- 

 gular and confused. 



From the outermost fibres of the axial skeleton there proceed 

 outwards to the surface, perpendicularly or nearly so thereto, 

 numerous short, non-plumose paucispicular columns of com- 

 paratively long and stout styli — the points of the (slightly 

 divergent) terminal ones of which impinge upon, or project 



