PORIFERA. II. 19 



a rather slightly curved shaft, the lateral alae of which are pointed and tooth-like, and of the same 

 length as, or a little shorter than, the tooth; the tooth may be narrower or broader, but, when viewed 

 just from the front, it is lanceolate and more or less pointed. Tuberculum is oval, most frequently 

 pointed, or lengthilv triangular; when the chela is seen a little from the side, the tooth and tuber- 

 culum appear more pointed. The length of the chela is somewhat varying, from o-038 mm to o-c>5 mm ; 

 the thickness of the shaft is ca. ooo4 mm . Most frequently these chela; are a little twisted, so that the 

 two teeth are not quite in one plane. Of this chela I have seen a few developmental forms, but only 

 rather grown ones with half-developed tooth and alae. 3. Sigmata; these are more or less contort; 

 they reach to a rather considerable size, but are very varying in this respect, the length being between 

 o-03 ,nm and o-o85 ,nm , and the thickness proportionally 0-002— o-oo6'" m . These sigmata show an interesting 

 fact well worth to be noticed. Towards the bendings the shaft generally shows a slight expansion 

 (as seen in Pl.VIII, fig. 5 g); this is not owing to the shaft here being thicker, but to the fact that it is 

 somewhat compressed. When a sigma is seen under the microscope, the hook that on account of the 

 twisting is turned towards the beholder (in the figure the upper one), appears also narrower than the 

 other, and the compression may also be seen on broken sigmata where a transverse section is seen; 

 the transverse section seems to be somewhat triangular with the narrowest edge turned inward. Of 

 these sigmata developmental forms of different thickness are not rarely found; the finer they are, the 

 less developed are the recurved ends; in the very finest ones, of a thickness of scarcely o-ooi mm , the 

 recurved ends are not yet formed. The mentioned structure of the end parts of the shaft may already 

 be traced in the developmental forms. 4. Forcipes; these are of the common, more or less hairpin-like, 

 form with a round curve above and two more or less parallel legs; the legs are most frequently slightly 

 diverging, but may also be quite parallel, or slightly converging, the latter, however, being perhaps only 

 apparentlv the fact and owing to a twisting. They are thorny, which is, however, on account of their 

 smallness, only very little conspicuous; the legs end in a quite small knob-like swelling. When the 

 forcipes are seen under sufficiently great magnifying powers the thorns are seen to be found especially 

 on the inner side of the legs; they are comparatively long, and directed a little upward; also on the 

 upper side of the curve some smaller thorns are found, and there seems likewise most frequently or 

 always to be found a small thorn on the inner side of each knob. A slight granulation may also 

 in most cases be seen 011 the other parts of the forceps. Sometimes the legs are not of equal length. 

 These forcipes are exceedingly small and may easily be overlooked. Their length is o-oiy™" 1 , the 

 thickness at the curve, where it is greatest, is ca. o-ooi mm ; quite few, somewhat larger forcipes were 

 seen. The microsclera are found as well throughout the tissue as in the dermal membrane; in the 

 tissue sigmata are of most frequent occurrence, while in the dermal membrane the two forms of chela.' 

 seem to be found most frequently. 



Locality: The Davis Strait, depth 80—100 fathoms (Th. Holm), a couple of fragments. 



Remarks: This species has a quite interesting spiculatiou, and it is the first Esficr/opsis-species, in 

 which forcipes have been found. Therefore there might be some doubt with regard to its being referred 

 to this genus, and there might be a possibility of referring it to Forcepia Cart. As, however, the 

 species has no special dermal spicules, and thus wants a character very significant to the Myxillru\ 



