PORIFERA. I. 45 



frequenth' oval openings in the dermal membrane; tliey are measured to a size of o'oag — o-og™"'. Oscula 

 are found on the top of the cones, they have a diameter of 2 — 4"'™; each osculum leads into a shorter 

 or longer oscular canal, on the inside of which the excurrent canals open, and which passes below into 

 wide canals. From the oscular opening and downward in the tube the openings of the canals in- 

 crease in size. 



The skeleton consists of a network, less regular than in the i?r«/VTrt-species with a typical 

 unispicular skeleton. Polyspicular fibres consisting of about 4 — 6 spicules alongside run more or less 

 perpendicularly on the surface. These fibres (the primary ones) run in the oscular cones arcuately 

 upward and outward towards the surface which they pierce. The distance between these fibres has 

 about the length of one spicule; the fibres are connected to a rather irregular network by spicules 

 being tolerably perpendicular on the fibres, and consequently chiefly parallel to the surface, but these 

 spicules are most frequently found single, and do not form, or form only slightly marked fibres; they 

 ma^■, however, here and there form coherent, comparatively thick fibres. In the polyspicular fibres the 

 spicules are not lying in such a way as to have their ends in the same place of the fibre, that is to 

 say, they are not arranged in a bundle-like manner. Spongin is only present in a very slight degree, 

 and scarcel}- to be distinguished. 



Spicula are oxea; they are rather slender, and somewhat curved in the middle; a characteristic 

 feature of the species is that the ends are very much varying in form, from long tapering, often with 

 the point marked off, to quite shortly pointed, and even quite rounded; in a few specimens spicules 

 with rounded ends are frequent. The length varies between 0-17— 0-208™"'; a few still longer spicules 

 mav be found; the thickness is also somewhat different, from 0-005— o-oo8""". Shorter and finer needles 

 may be found, but in comparatively small numbers; these finer needles are very long tapering, but 

 all transitions to the other needles may be found, and consequently they may be taken to be stages 

 of o-rowth; during the growth the ends will thus increase comparatively more in thickness than the 

 middle part of the needle so that the fully developed spicule becomes less long tapering. Thus this 

 species is rather well characterized by its thin, most frequently rather sharply curved needles, which 

 varv very much with regard to their pointing, and whose ends often show a rounding or a tendency 



to such a one. 



I have had one of Fristedt's original specimens for comparison, and therefore I have been 

 able with certainty to identify the species. Fristedt also gives the size of his largest specimen to 

 be 6o™"\ but the largest tube of his specimen was 30'°™ high, and the osculum had a diameter of 6"'". 

 Fristedt says that the spicules appear in two thicknesses in the proportion 1:2. The fact, according 

 to m>- examination, is that the spicules vary evenly from ca. 0-005—0-008""", and besides some finer 



spicules are found. 



Locality: This species seems to be rather common, and has been taken at West-Greenland: 

 Julianehaab (inspector Ryberg), Holstensborg (Bergendal), Egedesmmde (Traustedt), and by the Ingolf 

 expedition at station 33, 67=57' Lat. N., 55° 30' Long. W., depth 35 fathoms; further it has been taken 

 at Iceland: Gfjord, depth 11 fathoms (H. Jonsson), Onundarfjord, depth 10 fathoms (the author), Eydis- 

 fjord, depth 14 fathoms (Horring); finally it has been taken at the Faroe Islands: to the east of Nolso, 

 depth 30 fathoms, and at Klaksvig, depth 11 fathoms (Th. Mortensen). 



