j- PORIFERA. II. 



most frequently midway between these limits, the thickness is croi8 — cro25 mm . Also in these styli a 

 widening of the axial canal is seen at the upper end, and this widening is generally found a little 

 below the end of this canal. 2. The dermal spicules are tylota; they are comparatively long and 

 thin with well-developed end-swellings, and they are straight, sometimes slightly curved. Their length 

 is 0-32 — o - 38 mm , and the thickness 0-0028 — 0'0035 mm . The two ends of the tylota are not quite equal, 

 the shaft is in one end a little thicker, while the swelling is here comparatively smaller, whereas in 

 the other end it is a little thinner, and the swelling is larger, often almost globular. To judge from 

 a few developmental forms, it is, however, this end which is originally pointed, b. Microsclera; these 

 are of three forms, chelse arcuatse and sigmata of two sizes. 1. Chelae arcuatse are of the same 

 form as the chelee in L'. complicata ; the shaft is rather highly curved, the ends are relatively small, and 

 tooth and alae are stubby. The length is 0-034— o-057 mm . The shaft is somewhat flattened, and in section 

 flatly elliptical, its thickness, from the side and from the front, is ca. 0-0028 — o-oo8 mm . A few develop- 

 mental forms were seen. 2. Sigmata of the small form have most frequently a more common 

 sigma-form as in the preceding species, they are comparatively small and fine, and they are plane. 

 Their length is 0-017 — o-023 mm and the thickness at most o-ooio mm . 3. Sigmata of the large form; 

 also in this species a larger sigma occurs, but in rather small numbers; it is of the common type, 

 more or less contort, 0-028 — o-033 mm long and ca. o-ooi4 mm thick. The microscleres are found throughout 

 the sponge and in the dermal membrane, where the large chela is especially frequent. 



As is shown by the description, this species is very closely allied to the preceding one, but is 

 distinguished from it by sure characters; these distinguishig characters are especially the longer styli, 

 a different form of sigmata, and, above all, a different form of the tylota. 



Locality: Station 19, 6o° 29' Lat N., 34 14' Long.W., depth 1566 fathoms. The bottom tempera- 

 ture was here 2°4 C. It is an interesting fact to notice that while the preceding species is a native 

 of the cold bottom, the present species, which is so closely allied to it, but is surely distinguished, 

 belongs to a bottom with positive temperature. The locality is situated in the southern Denmark Strait. 



8. L. stipitata n. sp. 

 PI. V, Fig. 13. PI. XVII, Fig. 2 a— e. 



Erect, stalked, club-shaped, somewhat compressed. The dermal membrane not especially thin, sup- 

 ported by bundles of dermal spicules and also provided with horizontal spicules. The skeleton dendritic ; 

 from the stalk polyspicular fibres pass up through the sponge, branching and anastomosing. Spicula: 

 Megasclera : the skeletal spicules smooth styli o-jp — o-6j mm , the dermal spicules tornota o-ji — 0-488"""; 

 microsclera of one form, chelce arcuatee 0-032 — 0-045""". 



This species is markedly club-shaped; it consists of a rather thin, cylindric stalk, which is below 

 attached to the substratum by a small basal expansion. The stalk is of equal thickness throughout 

 its length, and above it carries a head which is somewhat compressed and may best be described as 

 irregularly cordate. This part is compressed in such a way, that one side is convex and the other 

 flat or a little concave. The edge is rather sharp. The smallest specimens are only little or not at all 

 compressed. The largest specimen is 45 mm high, of which the stalk makes ca. 15™™ and the upper part 



