VEGA- EXPEDITIONEN SVENENSKAPILGA ARBETEN. 407 
to a chess-board, because of the structure of the radial tubes 
which resembles that of Ascandra Schmidtu H. "The mouth of 
eloaca is furnished with a ciliary fringe of very long acerate 
spicules. This peristome extends only one mm outside the 
true osculum, but > mm into the cloaca of the sponge. On 
issuing out of the sponge it is surrounded by a fringe of tri- 
radiate spicules. 
Skeleton. The skeleton consists of triradiate, quadri- 
radiate spicules, of large acerate from dermis and peristome, 
and of very minute, straight or slightly curved acerate spicules. 
Triradiate spicules (Plate 22, fig. 7—12). "These spicules are 
numerous and more variable in this species than in other 
Calceispongizxe which I have seen. The rays are often nearly 
of the same diameter and length, but there are not rarely tri- 
radiate spicules, which have two rays of the same size and the 
third shorter, as im fig. 4. 
Triradiate spicules of the radial-tubes, figured in Plate 
22, fig. 11, are very characteristic for this species; the lateral 
radii are not of the same length, the proportion between 
nernenoths bems 2 Triradiates spleules, figured in the 
same Plate, fig. 8, are not numerous and not typical for the 
species. 
Quadriradiate spicules (Plate 22, fig. 13). The spicule of this 
kind are exceedingly rare. The proportion between the apical 
and the other rays is about 2:41. 
hen lenotn of the rays of: the triradiate "and guadri 
radiate spicules varies very much. The length of the two 
short rays of the spicule, figured 12, is about 0,15 mm, all the 
other triradiate and quadriradiate spicules being figured in 
the same proportion. 
The large acerate spicules from dermis and peristome (Plate 
22, fig. 3-4). These spicules vary much in length: from 
one mm to 5 mm. The spicules of the peristome and dermis 
are almost of the same diameter, the first a little longer. Con- 
sequently the peristome is not as usual composed of linear 
acerate spicules. 
The minute acerate spicules (Plate 22, fig. 5—6). The spicules 
of this kind are exceedingly minute, being only 0,07 mm in 
