PORIFERA. II. 



o-on — o-oi2 mm . The needles chiefly forming the skeleton of the calyx-wall are of a somewhat different 

 form; they are straight or, more rarely, a little curved subtylostyli with a rather distinct, but small 

 head-swelling, placed a little below the end; they are only a little thicker in the middle than at the 

 upper end; the point is even, but not long. The length was measured from ca. 0-238 — o-475 mm , an< l 

 the thickness is 0-007 — o-oo8 mm . Besides these two forms short subtylostyli occur abundantlv in the 

 mentioned refolded edge; they are of quite the same form as the preceding ones, the length is from 

 o-i49 mm to about o-23 mm , and the thickness is 0-005— o-0O7 mm ; as mentioned, they occur onlv in the 

 refolded edge, but their size, which passes into the size of the other subtylostyli, seems to make it 

 doubtful whether these two kinds of subtylostyli are really different. The fourth form of megasclera 

 is the one most characteristic of the species; it is the long spicules projecting from stalk and calyx 

 and forming the crown at the top. They are long, thin styli running out into a very long and very 

 fine point. They are almost always evenly curved in the outer part; sometimes the curving is a little 

 irregular. Their length is very varying, it may be given to between 0-7 and r4 mmi ). The thickness 

 at the head-end is ca. o-oo5 mm . Down at the base of the stalk they seem to be shorter, and these short 

 needles often have a head-swelling. Among the projecting needles some are found of a very charac- 

 teristic appearance; in a shorter or longer portion of their outer part they have a series of ring-like 

 swellings, so that they get an appearance like a string of pearls; together with this feature they have 

 often a somewhat shorter point, and their length may then go down to o-65 mm , and they are likewise 

 often somewhat more robust, of a thickness of up to o-oi mm . As these needles have otherwise the 

 same form and occurrence as the other projecting ones, they are scarcely anything else than a 

 variation of the same type. The needles projecting from the axis are partly interwoven between the 

 parallel spicules of the axis, partly they are, a great deal of them, attached to its outside, b. Aficro- 

 sclera ; these are only of one kind, anisochelse palmata;, and they are of quite the same structure 

 as the cheke in infomdibulum ; their length is 0-017 — o-oio, mm aud the breadth o-oo8 mm . They are 

 present in great numbers and occur especially abundantly in the refolded edge of the calyx. 



This species seems to be closely allied to A. infundibulum, both on account of the outer form 

 and of the projecting, long pointed styli, but it differs from it among other things by other sizes of 

 the different forms of needles, and by the occurrence of peculiar, pearl-striug-shaped needles. These 

 spicules recall to some degree those in Meliiderma stipitata described' and figured by Ridley and 

 Dendy, but these latter are much shorter and shorter pointed. 



Locality: Station 78, 6o° 37' L,at. N., 27 52' Long. W., depth 799 fathoms; the station is situated 

 on the eastern slope of the Reykjanes-ridge. 



The genus Asbestopluma forms a well characterized genus, the species of which are also char- 

 acteristic in their exterior by being all of erect and symmetrical form, aud also the skeletal structure 

 shows great conformity. Outside this genus a similar form occurs in Cladorhiza, and among the 



') Exact limits for the length of these spicules cannot be given, as the outermost point is wanting in almost all 

 of them. 



The Ingolf-Expedition. VI. 2. IO 



