458 
mm in diameter are seen, but I think they are made by foreign 
organisms. 
The skeleton consists chiefly of scattered monactines, which are 
however here and there forming distinet fibres, ca. 60 jti thick; 
there is no special dermal-skeleton. 
Spicules. a. Megascleres. Styli orsubtylostyli (fig. 15a), 
straight or slightly undulated; generally thickest in the middle, 
apex sharp'pointed or sometimes blunt; 260—325 x 10 b. Mi- 
croscleres. 1. Tetrapocilli (fig. 15b—e). It will be convenient 
to start the description with the young stages (fig. 15b); here the 
spicule is distinetly seen to consist of a cylindrical shaft, which 
appears as formed by two parts, both nearly semicircularly curved 
and cemented together with end towards end; it appears so, but I 
think, that the two parts are really one spicule built in one cell; 
then both ends expand, forming disc-like plates, which are placed 
nearly, but never quite, at right angles to the axis of the shaft, 
and both to the same side. Also in the middle of the shaft two 
plates are being formed, which, so far as I am able to see, begin 
as separated, but later coalesce with their outer rim; they are 
standing perpendicularly towards the axis of the shaft, directed to¬ 
wards the same side as the terminal plates. The perfeet spicules 
(fig. 15 c—e) is then completed so, that the rim of all four plates 
is growing obliquely inwards as a fine lamella; thus four cups are 
built, situated in couples, with their hollow sides to each other, 
quite as if two lophon-hi^oQxWx were cemented together with the 
ends. Length from 40—80 ca. 50 p the most common. 2. Iso- 
chelae (fig. 15f), of common form, very thin and delicate, ca. 
15 p long. 
Guitarra bipocillifera nov. spec. 
(Fig. 16 a—f.) 
Colville Channel. 35 fathoms. Sand, mud. 21/X1I.1914. 
Several specimens; the largest one measures 290X65X32 mm; 
they are all roundish lump-shaped, the smaller ones nearly globular. 
The surface has a very characteristic appearance: it looks as if some 
animal had been gnawing shallow furrows all over the sponge, Ihese 
furrows now and then expanding to broad patches; in this way small 
and big “islands“ are formed; the furrows are 0 , 5—1 mm deep, and 
from a fraction of a mm to several mm broad; the dermal-mem- 
