8o PORIFKRA. II. 



s 



swelling, as described and figured by Sars. Sars says that the branchlets are generally arranged in 

 a circular way, my material is too much damaged to enable me to decide this fact with certainty. 

 The largest of my specimens is, inclusive of the root, 75" ,m high, but the specimen is not quite entire 

 above; the longest branch is 25 mm , and the thickness of the stalk is fully 2 mm . The small unbranched 

 specimens are 33 mm high. Thus this species would seem not to reach any considerable size; Sars 

 gives the height of his specimen to 6o mm , and the specimens from the North Sea and the Gulf of 

 St. Lawrence, mentioned by Schmidt and Lambe I.e., were smaller')- The colour of the sponge '(in 

 spirit) is white or slightly yellowish, often a little transparent; Sars states the colour in fresh speci- 

 mens to be transparently yellow. On account of the axial skeleton the sponge is rather stiff and not 

 very flexible; the outer layer of tissue is soft, and the branchlets are flexible. The surface is smooth, 

 and only at the end of the branchlets projects the supporting fibre. No distinct dermal membrane 

 was seen. Pores were not observed with certainty; here and there on the surface small circular 

 openings were seen, but on account of the bad state of the material I dare not with certainty regard 

 them as pores. Oscula were not found either. Nor have, as it is well known, pores and oscula been 

 mentioned before in this sponge 2 ). 



The skeleton consists, in the stalk and the branches, of a compact, pohspicular axis, the needles 

 of which are parallel to each other and to the longitudinal direction ; the axis of the stalk, however, 

 is in the lower part somewhat spirally twisted. Below, the stalk, as mentioned, ends in a highly branched 

 root, the branches of which taper more and more, till they end almost with only one spicule, or with a 

 couple of spicules alongside each other. The branches on the stem are not inserted in the axis in the 

 same way, as are the branchlets; it may rather be said that a cleaving takes place, some spicules by 

 degrees bending to the side and forming the branch; in the angle between the stalk and the branches 

 some spicules are found running evenly arcuately between the stalk and the branch, so that the angle 

 is not seen sharply, but as a rounded curve. The skeleton of the branchlets is formed by a fibre pas- 

 sing through the branchlet to its end. It decreases in thickness outward, and accordingly it has here 

 fewer spicules than farther in, most frequently it has here only a couple of spicules alongside. The 

 fibres of the branchlets are inserted in the spicula-axis of the stalk or the branches, between the 

 spicules of these axes, and they pass in to the centre, where, when several branchlets are placed at 

 the same height, they meet. The part of the fibres of the branchlets that is inserted in the axis, is in 



M Wyville Thomson states (The Depths of the Sea, 112), in a general and, otherwise, somewhat vague mention of 

 C/ador/i/za-spec\es or Cladorhisa-\Cs.e. forms, that they may reach to an extent of 50 — 80cm. He says that at least three species 

 occurred. It is not possible to decide, which species his statement refers to, but I suppose it is to the following ones 

 C. abyssicola is surely not among them, and we see also that the stations mentioned by Carter (Ann. Mag. Nat. Hist. Ser. 4, 

 XVIII, 319), at which Cladorhiza-ioxms were taken, have, all of them, negative bottom temperatures, while abyssico/a occurs 

 on bottoms with positive temperatures. 



2 ) Ridley and Dendy (Challeng. Report, 87) say, under the species mentioned by them as C. abyssico/a var. rect- 

 angulai-is: The anatomy of the soft parts of this remarkable species has always been a mystery . I do not see that this is 

 to be said especially of this species. That pores, oscula, and canal-system have not been described is a fact that holds good 

 of many sponge-species, and especially with regard to this sponge Sars has given several details beyond what is known of 

 many other species. When he says that in the layer of tissue absolutely no canals or cavities can be discerned , this of 

 course, is only the expression of the fact that he has not seen them; in the comparatively thin layer of tissue, the canals, no 

 doubt, are small, and scarcely to be observed without special preparation. Ridley and Dendy have not been able to 

 examine their specimen (which otherwise assuredly does not belong to this species) anatomically, as their material was dried, 

 but they have not taken the opportunity either of examining anatomically any of the other C/adoi-Zaza-species they have 

 described. 



