PORIFERA. III. 35 



the fibres are formed of the smooth tornota. The skeleton in the oscular cone is formed of parallel 

 tornota, outwards it has acanthostrongyla. In the axis a distinctly observable amount of spougiu 

 is found. 



Spicula: a. Megasclera; i. The skeletal spicules are tornota, they are straight and slightly 

 fusiform and slightly, but rather distinctly polytylote or show at all events an uneven contour; 

 the ends are rather short and somewhat stubby. The length is 0-40 0-53 mm , and the thickness 

 is 0-007 o-on mm . 2 - The dermal spicules are acanthostrongyla, they are slightly curved or some- 

 times straight and of the same or nearly the same thickness in the whole length; the spinulation is 

 dense and coarse, and the spines are generally longer than half the diameter of the spicule; the spines 

 are placed a little more densely at each end. The length is o-i 10-19""", and the thickness 0-005 o-oi2 mm . 

 Whether these spicules are really and primarily diactinal, I have not been able to decide, as no young 

 developmental stages occurred; the shape of the spicule does not point towards a monactinal origin, 

 as also the few older developmental stages, I have seen, are quite diactinal; also the curvature, which 

 is not localized at one end, but nearly always goes evenly from the middle towards both ends, points 

 towards a real diactinal spicule, as also does the fact, that the spines on both halves are somewhat 

 recurved towards the middle, while those standing in the middle are directed straight out On the 

 other hand the dermal spicules occurring in the embryos are monactinal (see below under Embryos.) 

 b. Microsclera; these are of one form, chelae arcuatse; they have an evenly curved shaft, lobe-shaped, 

 somewhat pointed alse and a pointed elliptical tooth of the same length as the alse. The length of 

 the chelae is 0-024 0-028 mra , an d the thickness of the shaft is 0-0021 0-0028 mm . The chelse occur 

 numerously in the pore-membranes and the oscular wall, but also otherwise round about in the tissue. 



Embryos: Also in this species embryos were found round about in the tissue in great numbers; they 

 are globular, of a diameter of about 0-29 mm . They were found both with and withotit spicules. The 

 spicules are either only chelae or chelae and dermal spicules; the chela; seem thus here to be the first 

 occurring spicules, and next the dermal spicules; in single cases only developmental stages of chelae 

 were found and some few, thin developmental stages of dermal spicules. The dermal spicules were 

 not, as is elsewhere generally the case, fine developmental stages, but on the contrary with regard to shape 

 fully developed spicules; they were, however, smaller than in the grown sponge, viz. 0-085 mm ; both 

 these spicules and the developmental stages were monactinal with one end pointed. 



This species is, as seen from the description, very nearly related to G. pyrula; the outer shape 

 and the skeletal structures are the same, only in the spicules is a difference present, but this differ- 

 ence is constant; the differential character lies in the dermal spicules, these being in gelida always 

 diactinal and of the same thickness in the whole length, and they are on the whole characteristically 

 different from the acanthostyli in pyrula; if the difference had only consisted therein that the pointed 

 end here was rounded, no stress would have been laid upon this fact; further the tornota are 

 distinctly polytylote and have stubby ends, and finally the chelae are larger. To be sure I have only 

 had one specimen of the species, but as this also shows a special condition with regard to locality, 

 being an inhabitant of the cold area, I have no doubt, that the species is certain and distinct. 



Locality: Station 116, 70 05' L,at. N., 8 26' Long. W., South of Jan Mayen, depth 371 fathoms 

 (bottom temperature -=- o 4 C.). One specimen. 



5* 



