x 62 PORIFERA. II. 



it becomes by degrees elliptical during the growth. In the youngest forms the alse are only seen as 

 a little more marked expansions at either end of the thin lateral parts. The very finest forms are 

 cylindrical. 2. The chelse of the middle form are considerably smaller; they have a rather highlv 

 curved shaft; the terminal parts are considerably larger than in the large ones, so that the free part of 

 tne shaft is only about one third or a little more. The tooth is rather narrow, the alse are of the same 

 length as the tooth, and their lower edge is indented, so that they have a somewhat tooth-like form 

 when seen from the side. Their length is croi8 — o-c>28 mm , and the thickness of the shaft is ca. croo2i 

 — o - oo28 mm . Quite singly chelse are seen that seem to occupy a position midway between these chelae 

 and the preceding form. 3. The smallest chela is of a peculiar and very characteristic form. It is 

 highly curved, and the terminal parts are so large, that the free middle part of the shaft is less than 

 a third of the whole length; but when the chela is seen from the front, the terminal parts are, on 

 account of the curving, seen a little from the end and therefore shortened, so that in a frontal figure 

 the terminal parts and the free part of the shaft will be of about equal length. The tooth is narrow 

 and shorter than the alse, and their lower edge is almost not indented. The chela is very small, its 

 length is o-oio— o-oi5 mm , and the thickness of the shaft is ca. crooio mm . On account of the form of the 

 alee this chela approaches the palmate chelse, but on account of its strong curving and the narrow 

 teeth it is more properly referred to the arcuate chelse. 4. Sigmata are of the common form, and 

 are more or less contort, up to one fourth of a turning. They are very varying in size, the length 

 from o - o23 — o - o85 mm , and the thickness proportionally from crooi — o-oo3 mm . The microscleres occur 

 throughout the sponge, especially in all membranes; the large chela, as mentioned, is particularly con- 

 spicuous both in the dermal membrane and in the membranes of the canals. 



Locality: Station 10, 64° 24' Lat. N., 28 50' Long.W., depth 788 fathoms; station 85, 63 21' Lat. N., 

 25 21' Long. W., depth 170 fathoms; 62° 36' Lat N., 3° 21' Long. E., depth 198 fathoms (Ad. Jensen, the 

 cruise of the « Michael Sars» 1902). Four fragments in all. The localities are situated in the Denmark 

 Strait and off the western coast of Norway. 



5. L. indistincta Frstdt. 

 PI. V, Fig. 10. PI. XVI, Fig. 3 a— h. 



1887. Hastatus indistinctus Fristedt, Vega Exp. vetensk. Iakttag. IV, 444, PI. 25, figs. 13 — 19. 



Massive, more or less lobate. The surface slightly grooved or smooth, very finely shaggy. The 

 dermal membrane not especially thin, supported by erect or more or less recumbent bundles of dermal 

 spictdes. Oscula scattered, few. The skeleton an irregular, mostly polyspicular reticulation ; longer fibres 

 passing towards the surface may be found; sometimes the reticulation is more diffuse and unispicular. 

 Spicula: Megasclera: the skeletal spicules slightly and dispersedly spined, sometimes smooth, styli O'jj— 

 o-jo'"'", the dermal spicules tornota or tornostrongyla 0-20 — 0-29"""; microsclera of three forms, chela 

 arcuata of two forms, large ones 0-018—0-044""" , small peculiar ones o-ooS— o-oif"'" , sigmata 0-026 

 — o-o$ mm . 



This species has chiefly a massive, more or less lobate form. It may grow expanded on the 

 substratum, and from the expanded part, which grows to a considerable thickness, round projections 



