l6 PORIFRRA. III. 



2. H. coriacea n. sp. 



PL II, Figs. 5-6, PI. IV, Fig. 5. 



Elongate, somewhat fusiform, sometimes cylindrical or more irregular and somewhat branched; 

 provided with generally short, papilla-shaped fistula in greater or smaller number. Growing freely, with- 

 out attachment. Surface somewhat rough, but without projecting spicules. The sponge is surrounded by 

 a very solid dermal layer. Oscula and pores each at the summit of their own papilla*. The dermal 

 skeleton formed of close-lying, tangential spicules. The skeleton of the inner body consisting of scattered 

 spicules. Sficula: megasclera of two forms, slrongyla with spinulous ends 0-24 — ro2""", acantiiostrongyla 

 o'T2 — o-2j8 mm . No microsclera. 



This species has an exterior which certainly resembles that of the preceding species but how- 

 ever is somewhat different, and it is larger and more robnst. It consists of a body with fistulse, but 

 the body is never globular but elongated, generally somewhat fusiform, thickest in the middle and 

 somewhat tapering towards the ends; it is otherwise generally more or less irregular. Sometimes it 

 is not fusiform, and the sponge is then nearly cylindrical; sometimes it is somewhat branched. The 

 fistulas are generally rather short, often nearly papilliform and they are for the rest very irregular 

 both in shape and arrangement, and they may also be branched. When they are somewhat larger 

 they appear as branches, so that the sponge then assumes the branched shape. Most of my specimens 

 are somewhat damaged, but to judge from not damaged specimens the species is not attached, but 

 grows freely, which is also by far the most probable. The largest specimen, which is not quite entire, 

 has a length of about ioo mm and a greatest thickness of 17 mm ; the other specimens are somewhat 

 smaller, down to about 50 mm in length. The colour (in spirit) is in most specimens whitish grey or 

 dirty greyish violet, the inner body is darker than the dermal layer and is obscurely reddish violet; 

 some of the smallest specimens are nearly cpiite white, but also in these the inner body is somewhat 

 darker. Whether the colour is original or due to the influence of alcohol has not been observed. 

 The consistency is, on account of the very thick dermal rind, very firm, the inner body is also in its 

 present condition rather firm, but brittle; it is strongly contracted and lies generally up to one side of 

 the dermal layer. The surface cannot be termed smooth as the close-lying spicules cause it to be 

 rough both to the sight and to the touch, but it has no projecting spicules. The sponge is outermost 

 surrounded by a very solid and hard dermal layer, provided with close-lying spicules; this layer is 

 very thick, from 0-4— cr8 mra . Pores and oscula: Some of the fistulae or papillse are oscular papillae; 

 they are distinguished by their conical shape, pointed towards the end, with an oscular opening 

 at the summit. The papilliform ends of the sponge-body itself are oscular papillae. From the 

 oscular opening a canal, which is surrounded by a film-like membrane, leads down into the body. 

 The other papillae, which bear no oscula, are pore-papillae. These fistulae or papillae are of a different 

 shape from the oscular papillae, they have rounded ends which are as a rule a little swollen; they are 

 present in greater numbers than the oscular papillae. The pores are only present in the outermost, 

 rounded end-part of the papillae. In the middle, through the interior tissue of the papilla, runs a canal 

 which in the outer end-part of the papilla is divided into branches; these branches go to the surface 

 and are the incurrent canals into which the pores lead; these latter are lying in an irregular reticulation 



