i6o 



PORIFERA. II. 



the tooth is most frequently elliptical, but may vary rather much in form, be more narrow or broader, 

 and rounded or straight cut off at the end; it is of the same length as the alse; the lower edge of 

 these is somewhat indented, so that they get a tooth-like form, but they may be somewhat varying 

 in form, as upon the whole the chela may vary rather much in appearance. In a few individuals 

 peculiar deformities occurred rather frequently. The size of the chela is somewhat varying, the length 

 is between 0-037 — oo6o mm , the smallest ones occurring most rarely; the thickness of the shaft is ca. 

 0-005 — o-oo7 mm , it is not cylindrical, but somewhat compressed. Developmental forms at different stages, 

 the youngest ones quite fine, were seen in rather small numbers. 2. Sigma t a are distinguished by 

 being very fine; they are otherwise of the common form and more or less contort. Their length is 

 0-018 — o-025 mm , they are so fine, that their thickness is only ca. o-ooo7 mm . Both forms of the microsclera 

 occur through the whole sponge and are rather frequent in the dermal membrane. 



Remarks: Although I have not examined Fristedt's type specimen, I take the determination 

 to be quite sure, as description, measures, and figures agree very well, thus especially the figure of 

 the fine sigma. Fristedt does not mention that the styli may be finely spined, but this feature is 

 easily overlooked, or he may have had a specimen with almost exclusively smooth styli. The speci- 

 men figured by Fristedt I suppose to be the lower part of a larger individual. The name fragilis 

 is well adapted to the brittle consistency. 



Localify : Station 85, 63° 21' Lat. N., 25 21' Long. W., depth 170 fathoms; 66° 20' Lat. N., 25 12' 

 Long. W., depth 96 fathoms (Wandel); 62 53' Lat. N., 9° 06' Long. W., depth 245 fathoms, 62 26' Lat. N., 

 4 49' Long. W., depth 228 fathoms, 62 36' Lat. N., 3 21' Long. E., depth 198 fathoms (Ad. Jensen, the 

 cruise of the « Michael Sars> 1902); at the northern end of Nolso, depth ca. 100 fathoms (Th. Mortensen). 

 The localities are situated in the Denmark Strait, round the Faroe Islands, and at the western coast 

 of Norway. 



Geogr. distr. The species is hitherto known from the Koster Islands at the coast of Bohuslan, 

 depth 95 fathoms. It is thus distributed from the Denmark Strait to the coast of Bohuslan, and its 

 bathymetrical range is from 95 to 245 fathoms. 



4. L. diversichela n. sp. 

 Pl.V, Fig. 9. PI. XVI, Fig. 2 a— h. 



More or less irregularly thick leaf-shaped? The surface almost smooth. The dermal membrane 

 a thin film supported by pcnicillate bundles of dermal spicules. The skeleton a polyspicular, irregular 

 reticulation, forming triangular to quadrangular or irregular meshes, here and there longitudinal fibres. 

 Spicula : Megasclera : the skeletal spicules rather densely spined acanthostyli 0-34 — o-42p mm , the dermal 

 spicules tornota 0-238 — 0-28""": microsclera of four forms, chela: arcuatcB of three forms, large ones 0-04? 

 — o-oji""", middle ones o-o/8 — 0-028""". small ones of peculiar form, highly curved, o-ow — 0-0/3""". sigmata 

 0-023 — 0-083'""'. 



Of this species, which is interesting on account of its chelae, we have only fragments, so that 

 nothing definite can be said of its form. The largest specimen is of an erect, compressed, but somewhat 

 irregular form (Pl.V, Fig. 9); a smaller fragment is likewise compressed. The form may, according to 



