17 
b. Skeleton. 
The skeleton is formed by a great quantity of spicules radiating 
from the centrum to the periphery where is formed a stout cortical 
layer by the globulates. The elements of this ordinary Geodine- 
Sponge-skeleton are the following spicules. 
1° ac? (f). In both varieties there are very much acerate spi- 
cules [ac?] or sub-fusiform acerate ones [ac? (f)] of different kinds. 
Some of them are very sharp pointed and slowly diminishing as 
in fig. 29, Pl. II. (var. «), other ones are thick nearly till the end 
of the spieulum, the top being rather teat-shaped, as in fig. 30, 
Pl. II. (var. z.); these are the excentric forms; many are between 
them, and form all possible transitions (fig. 31, 32, Pl. IL.). The 
length as well as the diameter are nearly in all specimens the 
same. Among these large acerates there are also a few small ones 
(fig. 33, Pl. D). 
2° tr, ac (acuate spinulate). There are known but a few species 
of Geodia, which possess this kind of spieules. In the first place 
Geodia stellosa Czern. It is not impossible that our /sops pallida 
is but a variety of @. stellosa Ozern. But as the representation 
of the spieules given by Üzerniawsky is rather schematized and 
the latin description is not sufficient, so I cannot identify both spe- 
cimens. Bowerbank has deserihed in Proc. Zool. Soc. ’72. pag. 630 
his Pachymatisma areolata, again one witb spinulate spicules. As it 
is characteristic for this Sponge that the oscula are „congregated in 
the deep areas of the surface”, so I believe that there is no doubt 
that it is another species, however it is true that the shape ofthe 
spicules agree very much. Finally Oscar Schmidt has described a 
Geodia with tr°. ac. to wit @. globus. Also Schmidt gives a des- 
eription that is much too short and without doubt is incomplete. 
Schmidt himself has stated in his „Spongien des Meerbusens von 
Mexico” that he has overseen the stellate spieules ofthe Geodidae; 
so it is very probable that @. globus possesses stellate spieules and 
perhaps also other forms of spicula. Schmidt has found in his @. 
globus only bifurcated anchors; for this reason I cannot indentify this 
with /sops pallida. Perhaps one will find afterwards that @. globus 
VOSMAER, Sponges. b 
