PORIFERA. II. 



45 



1887. Cladorhiza Nordenskioldii Fristedt, Vega-Exp. vetensk. Iaktt. IV, 455, PI. 25, figs. 56 — 59, PI. 31, 



fig- 25. 

 1896. Cladorhiza Nordenskioldii Lambe, Proceed, of the Roy. Soc. of Canada, Ser. 2, II, Sect. IV, 189, 



PL I, figs. 9, 9 a — f. 

 1901. Asbcstopliuna pennatula Topsent, Resultats du Vovage dn S. Y. Belgica, Spongiaires, 24 et 28, 



PL III, fig. 9 a— d. 

 1903. Cladorhiza pennatula Thiele, Archiv fur Naturgeseh. 1903, 385. 

 1903. Esperella plumosa Arnesen, Bergens Museums Aarb. 1903, No. 1, 11, Taf. II, Fig. 1, Taf. IV, Fig. 3, 



Taf. VI, Fig. 7. 



Slender, penniform ; the axis a little eompressed and the more or less long lateral branches in- 

 serted in flie narrow sides. The axial skeleton with a rather powerful, close-spiculed exterior layer. 

 Spienla: Megasclera styli in the axis o-68—i""", subtylostyli in the brandies and in the outer layer 

 of the axis 0-52 — o^j""", irregitlarly sinuous, minutely spinulous tylostrongyla in the eoating of the 

 stalk 0-05— o-ij/""" : mierosclera of three for vis, anisochelce palmata of two forms, the characteristic ones 

 o-o/o — 0-0114""" . the large ones with the lower end polylobate 0-048 — o-o6j""", sigmata 0-021 — 0-024""". 



By the description of Schmidt cited above this species would not be recognizable; the recog- 

 nition has only been possible by the description and figures of Topsent I.e. The species is erect and 

 more or less penniform. It consists of an axis carrying for some way above a row of rather short 

 lateral branches on either side. At the base the axis is somewhat thickened. All the specimens in hand 

 are broken off below, but judging from the best preserved specimens and from stalk-fragments that 

 must be of the lower part of the stalk, the stalk is here provided with more or less numerous, rather 

 short lateral processes placed irregularly so as to form a kind of root. This part is presumably im- 

 bedded in the mud, and the consequence is that the sponge is generally broken by the trawling, so 

 that the root-part does not come up. Above the lower part the axis is regularly cylindrical and con- 

 tinues so till the spot where the branches begin. Here it becomes somewhat compressed, in such a way 

 that the lateral branches issue from the two narrow sides. There may be some difference in the length 

 of the part carrying the lateral branches as compared with the total length. The greatest length of 

 the lateral branches is up to 5 mm , in one case lip to j mm , but they may decrease in length and be so 

 short as to be almost imperceptible. With regard to this fact the case may be somewhat different: either 

 all the lateral branches may be long, or all short; or as well' long as short ones may be found, and 

 then they are generally placed in such a manner, that the short ones are found below, the long ones 

 above. One's first impression is that the lateral branches, when short, are damaged or more or less 

 broken off. The case is, however, that the branches, when long, are quite thin and tapering outward, 

 the thickness- is about o-i — o'2' n,n . The distance between them, which is, however, far from being 

 equal, may be put down to about i mm . Now the more the branches are shortened, the thicker thev 

 become, and the smaller becomes the distance between them. When shortest they form a series of 

 quite slight, more or less confluent projections along either side, so that the the sides appear slightlv 

 indented or sinuous. These quite short lateral branches show no trace of damage or fracture, and 

 the spicules projecting from them are entire. Accordingly the feature cannot be owing to damage. 



loc f a y v a \ 



