1162 
Supposing the general structure of “Crambe” to be entirely different 
from that of Lithistids,there remainevident!y two other possibilities: either 
the desmas are formed by Crambe itself or they are not. In the 
former case the desmas would no longer be especially characteristic 
of Lithistids. In the latter case they are corpora aliena as occur 
so frequently in sponges. 1 hope to make it probable that this is really 
the case. 
Among the sponges I collected in Naples, there are several 
specimens in which such irregular spicules oceur as found in 
Crambe. In working out the Desmacidinae for the “Fauna and 
Flora of the Bay of Naples” I provided each specimen which 
is mentioned therein with successive numbers. In the following I 
will use the same numbers, so that everything can be checked and 
compared with the numerous illustrations, when the monograph is 
published. \ 
There are in the collection from Naples two specimens, 977 and 
1039, which form thin red inerustations on barnacles. The skeleton 
is mainly composed of styl, with a few strongyla. From the sub- 
stratum start more or less vertical bundles, generally beginning with 
a single stout stylus, around which slenderer styli are situated. 
Such a bundle may bifureate and the two branches may bifurcate 
again. At any rate the bundle terminates in a flat tuft of diverging styl. 
The shape and size of the styli vary slightly ; the maximal length of the 
stout styli is435 u in 977 and 480 u in 1089; the slender styli vary 
between 200 u and 280 u in 977, between 170 u and 300 u in 1039. 
A third specimen (1153) appears as a red crust on Luspongia. No 
doubt the three specimens belong to the same species. In all three 
we find chelae of the sort Lrvinsen (1894 p. 4) calls “anchorae”; 
they are tolerably frequent in 1039, but rather scarce in the two 
other specimens. Externally in no way distinguishable from 977 and 
1039 is specimen 1090. It forms likewise a bright red crust on 
barnacles. However, here no chelae could be discovered at all; on 
the other hand a few acantbostylt oecur. In six other specimens 
(967, 975, 1026, 1087, 1040, 1127), in which chelae are present, 
though sparingly, | found likewise some few acanthostyli. Specimen 
1040 is especially remarkable because distinct acanthostyli are exceed- 
ingly rare, but on many styles vestiges of spini are visible *). All 
these sponges appear as scarlet crusts and most certainly belong to 
the same species, as their general structure shows. If this be so, the 
presence or absence of acanthostyli or chelae (‘‘ancorae’’) has no 
specific value in the present case. With rare exceptions, chelae are 
') The illustrations are all ready for the monograph. 
