PORIFERA. I. 



39 



the fibres near one surface ha\-ino; another direction than those near the other surface; upon the whole 

 their course is rather irregular. In the nodes the skeleton is united b>- a clear, slightly yellowish 

 mass of spongin; in the polyspicular fibres the spicules are arranged in bundles, so that the ends of 

 spicules King alongside of each other, are in the same j^lace; accordingly the spongin uniting these 

 ends, form yellowish transversal bands across the fibres. 



Spiatla are oxea, sharply, almost hastately pointed, with a fairly long point; the}- are slightly 

 and evenly curved or more rarely straight; a characteristic feature is that most frequently they are a 

 little thinner in the middle than towards the ends, by which the pointing becomes more hastate. The 

 length is rather constant ca. 0-238'"'", deviating a little to both .sides; the thickness varies between 0-009 

 and 0-0I2"'"'. 



Locality: Of this beautiful species, so characteristic as well by its exterior as its spicules, we 

 have one specimen, not quite complete, from station 91, 64^44' Lat. N., 31' 00' Long. W., depth 1236 

 fathoms. 



From station 36, 61 50' Lat. N., 56°2i' Long. W., depth 1435 fathoms, and station 73, 62^58' Lat. N., 

 23°28' Long. W., depth 486 fathoms, the collection contains some small specimens, which I dare not with 

 certainty refer to the present species; they agree with this with regard to the form and size of the 

 spicules, as also with regard to the main features of the skeletal structure; only the oscular canals 

 seem to be less marked; but as these specimens, which are considerably smaller than the described 

 one, are surel)- )oung ones, this difference may perhaps be due to this fact; therefore I think it 

 probable that the\- belong to this species. — From station 89, 64"45' Lat. N., 27^20' Long. W., depth 

 310 fathoms, and station 105, 65°34' Lat. N., 7°3i' Long. W., depth 762 fathoms are further found a 

 few small fragments of the same skeletal structure as parenchyma, but the spicules have most 

 frequently a length of ca. 0-26"'"' and a thickness of o-oii""™; thus the}- are a little longer than in the 

 specimen described, but otherwise they are of the same form, and as the spicules of parenchyma may 

 reach the given length, it is rather probable that they may belong to this species; the fragments, 

 which are both basal parts, are too small to admit of a certain dertermination. 



3. R. folium n. sp. 



PI. V, Fig. 5, PI. XI, Fig. 5. 

 Ei'ccf, irregularly Icafsliaped, tlir leaves may be irregularly coalesced. The dermal membrane is Ihin, 

 zvitliout spicules; flic ends of the fibres project making the siirface finely sliaggy. Oscnla small, mnnerous, 

 only found on one side. The skeleton forms a regular network of primary a)id secondary fibres ; the 

 fibres are unispicular. Particular polyspicular fibres rzmning longitudinally, are found. Spicula are 

 slightly curved, rather gradually tapering oxea, o-ig — o-2i""". 



Of this species there are in the collection six lamellse, which, however, are more or less damaged, 

 and thev are like!}- to be fragments of only a couple of specimens. The sponge is formed as erect, 

 irregularly leafshaped lamellse, which ma}- be irregularly coalesced reciprocally, and, judging by the 

 material, they have been attached with a broad base. The specimens in hand have a height of ca. 

 100™™, and the thickness of the lamellae is in the middle up to 5'""', but decreases towards the margin. 

 The consistency is rather .soft and flexible. Here and there the surface has irregular, slightly projecting 



