PORIFERA. III. 



45 



swollen, and the shaft tapers into a long, fine apex. The spinulation is both in the large and in the 

 smaller styli restricted to about the lower half part; in the small styli there are, however, generally 

 some scattered spines more apically. The spines are only somewhat large on the head, outwards they 

 become small and still further outwards they are small grits, but generally more or fewer larger 

 spines are found between them. The spines are directed straight out, not reclined. The length is 

 o-j-j 0-51 mm , and the diameter of the head is 0-014 0-025 mm . The s tyh are n t divided into two 

 separate groups, but the intermediate sizes are rare. 2. The dermal spicules are rather large, 

 straight strongyla; one end is generally a little thicker than the other, but this feature is not always 

 distinct; the thicker end, or both ends may be quite slightly swollen; the shaft is slightly polytylote, 

 but sometimes this is hardly apparent. The length is 0-327 0-47""", and the diameter 0-007 o-oii mm . 

 b. Microsclera, these are chelae arcuatae; they have an evenly, not specially strongly curved shaft; 

 the tooth is narrow, lanceolate, the alse are of the same length as the tooth, but they are relatively 

 narrow, they may therefore, in a certain view be of a somewhat claw-shaped appearance, and the 

 chela may remind one somewhat of an ancora. The length is 0-045 0-054""", the shaft is somewhat 

 flattened, the diameter .relatively from 0-0028 to 0-0057""". The chelae occur rather numerously scattered 

 in the dermal membrane. 



The slender, often straight styli, generally showing some large spines among the small, are 

 characteristic for this species together with the large dermal spicules and the large chelae with 

 relatively long, narrow alse. 



Locality: Station 113, 69 31' Lat. N., 7 06' Long. W., depth 1309 fathoms (bottom temperature 

 -~ioC), one specimen; Forsblads Fjord in East- Greenland, 72 28' Lat. N., depth 5090 fathoms (The 

 Amdrup Expedition 1900), one specimen. The species must, according to these localities, be a native 

 of the cold water. 



3. H. storea n. sp. 

 PI. V, Fig. 7. 



Incrusting; surface smooth? Spicula: megasclera; the skeletal spicules somewhat densely spined 

 acanthostyli with a globular head, the longer of them with a smooth apical part, o-roo-jo""*, not 

 divided into two groups; the dermal spicules polytylote strongyla o-2po-j7 mm ; microsclera small chela 

 arcuatce recalling in shape the palmate chela, G-OJJ o-ojS'" m . 



This species grows as extended but thin incrustations on stones; it reaches a greatest extent 

 of 65 mm , the thickness is very slight, below 0-5 mi ". The colour (in spirit) is whitish grey. In the 

 present state of the sponge the surface is densely and finely hispid, caused by the skeletal spicules, 

 but this seems to be due to the fact, that the dermal membrane is wanting for the greatest part; 

 where the membrane is present, the surface seems to be smooth. The dermal membrane is a thin 

 membrane, resting on the skeleton below. 



The skeleton. The dermal skeleton; the dermal spicules form a skeleton of bundles and fibres 

 stretching from the basal skeleton up to the dermis; the fibres run more or less obliquely or bend 

 horizontally under the membrane. The main skeleton is constructed in the ordinary way, consisting 

 of vertical acanthostyli not placed specially densely. At the base an amount of spongin is present. 



