84 



PORIFERA. II. 



ways and be of very different lengths, and while in the more regular forms they are most frequently 

 imbranched, they may here be subdivided. Finally anastomoses and coalescences may take place 

 between the branches in the most irregular way, so that the whole thing gets a quite confused appear- 

 ance; nay, even branches from different individuals seem to be able to coalesce. When such anasto- 

 moses takes place, it is always the spicula-axes of the stem and the branches, which touch each other 

 and are coalesced, and the fact is evidently owing to the presence of spongin 1 ). The stem and the 

 branches are set with branchlets or filiform appendages. They issue rather closely to all sides, and 

 no definite arrangement is to be seen. They are frequently directed somewhat upward or on the 

 branches somewhat towards the point, and in different individuals they may be of somewhat different 

 length. With regard to the size to which the sponge may grow it is impossible to say anything 

 definite on the basis of the material in hand, as all the specimens are fragments more or less. In one 

 of the largest fragments the stem has a height of ca. no mm ; another specimen measures, on account 

 of the very long branches, ca. i50 ram ; one of the most irregular fragments, in which stem and blanches 

 could no longer be distinguished, has a greatest extent of 230 mm . The length of the branches, as men- 

 tioned, may vary very much. The stems and branches are of about ecpial thickness, the maximum 

 of which may be given to ca. 5 mm , but it may be somewhat less. The branchlets or the filiform 

 appendages are thin, filiform, and a little tapering outward; their length may be somewhat varying, 

 the maximum is 5— 6 mm , and the thickness at the base does not exceed o^" 1 " 1 . In a few cases branchlets 

 may be found as only exceedingly short, conical projections. On account of the firm axial skeleton 

 the consistency of the sponge is hard, but, especially in the upper parts, somewhat flexible; the outer 

 layer is soft, and the branchlets, in spite of the fibre in them, are soft and flexible. The colour (in 

 spirit) is white to yellowish white. The surface is smooth, spicules project only at the ends of the 

 branchlets. An inwardly distinctly bounded and consequently easily separable dermal membrane is not 

 found; on the other hand the whole layer of tissue is easily separated from the axis. Oscula and pores 

 I have not been able to find, and therefore I take them to be closed. In the layer of tissue nothing 

 is seen of the canal system under slight magnifying powers, but the tissue is apparently of uniform 

 structure, the canals being very small. It is only in thin sections and under higher magnifying powers, 

 that the canals are seen. 



The skeleton is constructed as in the preceding species, and consists in the stems and branches 

 of a very strong polyspicular axis; the needles of this axis are closely united and connected by spongin. 

 They are chiefly parallel to each other and to the longitudinal axis, the axis, however, is most fre- 

 quently more or less spirally twisted, often so much, that the direction of the needles deviates con- 

 siderably from the longitudinal one. Also in the superficial part of the axis the needles are often not 

 quite parallelly arranged, but may intercross, owing to the fibres of the branchlets being inserted 

 between them. The needles of the axis are turned in different ways, now the point is turned upward, 

 now downward. As in the preceding species the branches are formed by a number of spicules bending 

 to the side, and, at all events, only the middlemost spicules of the branches reach in towards the middle 



■) Such irregular anastomoses (at all events in the same individual) seeui to be frequent in the C/ador/tiza-species, 

 and they will thus be mentioned again in the following species. It seems also to be this same feature, which is found 

 in the specimen of the socalled C. aiyssico/a var. linearis, figured by Ridley and Dendy (Challeug. Report, Monaxouida, 

 PI. XX, fig. 6). 



