PORIFERA. II. 



63 



1886. Esperella cupressiformis var. Lycopodium Levinsen, Dijmphna Togtets zool.-bot. Udbytte, 364, 18 b, 



Tab. XXIX, Fig. 12, 13, Tab. XXX, Fig. 15, 16 d. 

 1900. Esperella Fristedtii Lambe, partini, specimen uimm e tribus commemoratis, Transact, of the 



Roy. Soc. of Canada, Ser. II, VI, sect. IV, 21, PI. I. fig. 2 f — h. 



The axis slender with closely placed lateral branches issuing all round. The skeleton consists of 

 a spicula-axis divided into fibres, between which the fibres of the lateral branches are inserted; outside 

 of I lie axial fibres only a few scattered spicules. S fie 11 la: Megasclera styli 0-238 — 1-5"""; uiicrosclera of 

 two for/us, the characteristic auisochelcr palmatce 0-014 — o-oij""", forcifes 0-050 — 0-056""". 



In outer appearance this species reminds somewhat of A. bihamatifera. It is of a slender, erect 

 form; below it has a quite short stalk. The other part is set with thin lateral branches issuing all 

 round. In different individuals the branches may be of different length, which does not, however, ex- 

 ceed 3 — 3 - 5' nm . The question is also here, I suppose, of contractibility. In a single specimen in which 

 the branches are short, they are, as it were, somewhat coalesced at their bases, so that this specimen, 

 as to its exterior, may somewhat remind of the preceding species. One specimen is of a peculiar 

 appearance, showing no branches, but having all the part that in other specimens carries branches 

 closely set with projecting needles which are, however, collected into bundles on the lower part. 

 In a transverse section it is seen, however, that the projecting spicules, which are apparently evenly 

 distributed over the surface, are bundles, radiating from the middle towards the surface, and sprea- 

 ding to some degree so as to be spread in a penicillate way at the surface. The lateral branches 

 go off horizontally, or are a little directed upwards. The branches are quite short below where 

 they begin, and also at the top they are most frequently shorter than in the middle. The upper 

 end is of a peculiar structure, the branches here coalescing to a different number of longitudinal 

 keels, the edges of which are set with a dense fringe of projecting spicules. This structure may be 

 more or less marked, and seems also sometimes to be wanting, but when this is the case it is difficult 

 to decide whether the sponge may not be damaged. The specimens in hand that are not broken off 

 below are attached to pebbles; from the Kara Sea we have specimens attached to shells and tubes of 

 Pectinaria hypcrborea. The largest specimen (from the Kara Sea) has a length of I20 mm ; the stalk is 

 here very short, and its length cannot be given exactly, the projecting spicules of the stalk here, as in 

 many of the specimens, passing by so imperceptible degrees into the lower short branches, that no 

 distinct boundary can be observed. Below the stalk is fully i mm thick. Then we have individuals of 

 decreasing sizes, the smallest, apparently entire specimen is full}- 20 mm high. By far the greatest 

 number of the specimens are very slender and of equal thickness throughout their length; a few spe- 

 cimens are somewhat more robust and a little thicker in the middle, so as to be slightly fusiform. The 

 consistency is rather firm, but the sponge is flexible; the stalk is hard. The colour (in spirit) varies 

 from white to light brown. The surface, with the exception of the stalk, must be said to be smooth, 

 as spicules only project at the ends of the branches. The stalk, on the other hand, is very shaggy 

 from rather close-set, projecting spicules which pass quite evenly into the lower short branches. The 

 dermal membrane is without megascleres, and is distended by the skeleton of the branches; it is closely 

 filled with chelae. I dare not decide anything as to pores and oscula. A few, roundish apertures are 



