94 



PORIFERA. II. 



braiiclilcts arc found. The skeleton is of the typical Cladorhiza-structure, and consists of a central axis 

 with lateral axes and fibres for branchlels ; but all these features are covered by the tissue, which thus 

 forms a coating layer, from which only the short wart-like ends of the brandies project. Spicula: Mega- 

 iclera styli o-^6 — o"ji"""; microsclera of three forms, anisancorm unguifera with five teeth o-ojj—o-ojj""". 

 sigv/ata of tzvo forms, large ones with slightly curved shaft and the ends prolonged in a flagelliform 

 manner o-i$ — 0'i8 mm , small ones with compressed terminal parts o-o^f — o-oj-f""". 



This species has a peculiar appearance, quite deviating from the other Cladorhisa-species. It is of 

 erect form; whether it is fixed below by an expansion or attached by a root is not known, as my speci- 

 mens are broken below, and Carter's description is based on fragments. The species ma}' be described 

 as a stem, set closely and all round with short, thick, more or less coalescing branches. Most frequently 

 the branches are so short, that they may better be described as wart-like projections, only rarely they 

 are a litte longer. As the}' are placed closely and irregularly, the sponge gets a more or less tuberous 

 or round-lobed surface. The specimens in hand have, otherwise, an erect form, and are straight or a 

 little curved, and besides the mentioned branches they have no ramifications; some skeletal parts, how- 

 ever, indicate that the sponge may also divide into larger branches each of which is then of the described 

 form. The largest specimen has a height of ca. 28o mm , and the others are a little smaller. The 

 thickness, which, on account of the close-set, round-lobed projections, can only be given approximately, 

 is 10 — 20 inm . The length of the branches is at most i3 mm , and their thickness at the base up to o, mm . 

 On account of the powerful axes the sponge is stiff, also the consistency of the tissue is rather firm, 

 but brittle. The colour (in spirit) is yellowish white. The surface is of a peculiar structure; as ends 

 of fibres are projecting everywhere it is shaggy or prickly. Deep grooves or canal-shaped cavities going 

 into the sponge are found between the ends of the fibres, so that the surface gets a reticulate-grooved 

 appearance, what has been expressed by Carter in the name corticocancellata. The points of the branches 

 are generally rounded, and they have no grooves, but show an even surface, shaggy from slightly pro- 

 jecting spicules. All the part of the sponge that coats the axes is penetrated by a system of canals 

 and cavities connected with each other, but separated by parts and beams of tissue, and these canals 

 and cavities must be supposed not to belong to the canal system proper. As this structure is closely 

 connected with the skeletal structure, a more particular account of it will be rendered under the 

 description of the skeleton. The dermal membrane is a thin film covering the parts of tissue that 

 separate the mentioned cavities, and supported by some spicules. Pores and oscula ■■ As the mentioned 

 canals and cavities must be supposed not to belong to the canal system, their outer openings cannot 

 be oscula. Pores are found everywhere in the dermal membrane in the mentioned cavities; they seem 

 to be small, as I have not with certainty measured any of them to a greater size than oo65 mra ; I sup- 

 pose that these openings act both as incurrent and excurrent ones. Of course, it is possible that some 

 of the openings on the surface may be openings of real, excurrent canals; but this fact is scarcely to 

 be decided by an anatomical examination only. 



The skeleton. In spite of the deviating exterior form, the skeleton is constructed after quite 

 the same principle as in the other C la do rh/za -species. A thick, powerful , polyspicular axis of closely 

 united, parallel needles stretches through the middle of the sponge. This axis has below a thickness 

 of 4""". It is more or less spirally twisted, especially in its lower part. Lateral axes a little upward 



