S^ / PORIFERA. I. 29 



This species is of a ver\- irregularl\- lumpy or lobate form; deep grooves or furrows ma\ be 

 found, and projecting lobes seem sometimes to coalesce, so that narrow hollows may arise, stretching 

 far into the sponge. The largest specimen has a length of ca. ii'"'" and a breadth of 85'^"', the smallest 

 specimen that is of a roundish form, is ca. 4'^" long by a breadth of hardly 3'^"'. Among the .smaller 

 specimens one is of a depressed form with irregular deep furrows in the edges, another is formed like 

 a rather long staff, strong!}- and irregularly curved, of a length of about 7'^"'. Whether the sponge 

 has been attached or not, is not to be decided with certain t\- from the specimens in hand; most of 

 them, to be sure, are somewhat damaged, pieces being broken off, and thus they might be supposed 

 to have been broken off at the place of attachment; most things, however, favours the belief that the 

 sponge has not been attached, or only loosely stuck into the bottom; neither is the upper or lower 

 surface to be decided. The colour (in spirit) varies from dirtily dark gra>- or bluish gray to black 

 violet; in the interior it is dirtily gra>-. Such is the colour in most specimens, but in a couple of 

 instances it is differing; thus one specimen is grayish white, but has distinct remnants of the violet 

 colour, and another is brown gray. Whether the more or less black violet colour is the original self- 

 colour of the sponge, or it is due to the fact that the colour has altered in the spirit, or the sponge 

 has been discoloured b}- King in spirit together with other sponges, is now hardh" to be decided. That 

 it is the original colour of the sponge is indicated by the fact that it is most .strongly pronounced in 

 all the furrows and grooves, where the surface has not been exposed to being scraped. If in such 

 places we cut off a thin layer of the skin and examine it under the microscope, we shall see, above the 

 dense layer of spicules of the skin, remnants of a violet-coloured, exceedingly thin and transparent 

 membrane, mostly wanting in the places where the colour is less pronounced ; these remnants probably 

 are remnants of the epidermis of the sponge. The con.sistency is rather firm, fleshy and somewhat elastic. 

 The surface^ as has been mentioned, shows some larger and smaller grooves and folds, but is otherwise 

 smooth. The outermost layer of the sponge is marked off as a dermal layer of a thickness of ca. 0-2"""; 

 this la\-er has its origin from the fact that the spicules here are closely packed; they are lying in all 

 direction-s, often, however, in such a wa>-, that they are arranged somewhat like bundles, the spicules of 

 which are parallel to each other; in some places this disposition may pass into a partly band-shaped 

 arrangement; the spicules are chiefl\' arranged parallel to the surface, only a smaller number are placed 

 obliquely or perpendicularly on the surface; sometimes, however, some projecting spicules may be found, 

 but that, perhaps, is due to the contraction of the skin. Osaila have not been observed in the specimens 

 in hand. The pores seem in most places to be rather scarce, only here and there they are seen more 

 closely gathered in greater numbers; in such places the spicules in the skin ma>- show a coarse, net- 

 like arrangement, which, however, is only seen under the microscope. The sizes of the pores have 

 been measured from 0-03 — o-5i'""; often they do not go perpeudicularh through the skin, but more or 

 less obHquelv, and consequently the\- are easily overlooked, when the skin is examined from above; 

 thcN- continue as fine canals without au}- formation of larger sub-dermal cavities, but some of them 

 mav branch off under the skin as horizontal canals. If a piece of the dermal layer is cut off and exa- 

 mined under the microscope from the in.side, a rather large number of canals are seen to be cut through; when 

 in such a case no pores are seen b>' an examination of the outside of the piece, the fact is, I suppose, 

 that they are closed, or they cannot be seen on account of their oblique direction. The mentioned 



