92 



PORIFERA. r. 



difference may be found between different individuals. The thickness at the upper end is between 

 0'029 — 0-039"™, the longest generally not being the thickest. Considerably finer needles of about the 

 same length, and connected with tlie others by transitions, may be found, but only in small numbers. 

 Besides normally formed styli forms may rather frequently be found, in which the i^ointed end is 

 rounded, and then it may be thinner or thicker, so that we get strong\-la. 



As in the preceding species 1 have also in the present one down at the place of attachment 

 foiind irregularly formed, more or less sinuous and curved needles, upon the whole smaller than the 

 normal needles of the species. 



b. Microsclrra. i. Sigmata of two sizes: the larger ones have a regularh- bent shaft, and the 

 ends are recurved with a round bend, and form a rather large hook. These sigmata are always contort, 

 generally about a quarter of a turn. The length is rather constant, and is between o-og— o'lo'"™; the 

 thickness is 0-0035— 0-004'""'. ^^Iso finer sigmata, down to quite fine ones, are found, which no doubt 

 are developmental forms; they are of the same length as the fully developed ones. Besides being 

 found single, these sigmata very frequeuth- occur in bundles, sigmadragmata, and presumably the\- are 

 all developed in this wa\-. As far as I have been able to decide, each bundle contains always eight 

 sigmata; frequently bundles are .seen made up of fine .sigmata, but generally the\- have the full 

 thickness, and consequently the bundles are not disunited, until the sigmata are fully developed. The 

 small sigmata have a regular sigma-form; their length varies from 0-016 — 0-021'"'", the thickness is ca. 

 o-ooi'"'". They are never seen in bundles. 2. Rhaphides of two sizes: longer and shorter; the longer 

 rhaphides are hairlike and finely pointed, of a length of 0-15 — 0-17'"'" and a thickness at mo.st of 

 o-ooi""". These rhaphides may be seen singly, but the\- occur chiefly in bundles, trichodragmata, which 

 seem to be of a ver\- varying thickness. The smaller rhaphides are somewhat thicker than the longer 

 ones, and the\- are ftisiform; sometimes the greatest thickness is nearest to one end. The length varies 

 from 0-042 — 0-057'""', but most frequeuth' it is 0-05'""^, the thickness is 0-0015 — 0-002""'. These rhaphides 

 also occur in bundles, trichodragmata; the bundles are often seen to contain eight rhaphides, but there 

 seem also to be bundles with more needles. 3. Commata, small, comma-shaped styli of a similar form 

 as in the preceding species; the head end is .slightly swollen; the length is o-oii -0-014'""', and the 

 thickness at tlie upper end ca. o-ooi'"™. All the microsclera occur as well in the dermal membrane as 

 in the other tissue; of the two forms of sigmata the smaller are everywhere most abundant. 



(}nii)iiiil(C f Besides the silicious bodies mentioned before we find in this sponge a particular 

 form, viz. small silicious globules. There is, however, the peculiarit\- of the occurrence of the globules, 

 that they are not found in all individuals, and in the sponges where they are found, they occur only 

 in certain places, so that in many cuttings of the sponge thev are not seen at all, while in others they 

 are found in great abundance. There can be no doubt that these globules belong to the same kind 

 of bodies as will be mentioned below under D.gnniilaiidicaVxs\.A\.., and which I take to be genunula;; 

 thus the fact that the\- are not found constantly, ma}- also be understood, as an individual need not 

 at all times have these liodies. In the present .species I have not found them to form distinct round 

 capsuke, but have only found them scattered singly in the tissue, or in irregular loose heaps. These 

 globules \-ar\- in diameter from 0-004 — 0-008'"'". 



Locality: vStation 53, 63" 15' I^at. N., 15^07' Long. W., depth 795 fathoms, a couple of small spe- 



