Systematik, 231 
fixed to the mud. The sarcode mucilaginous, studded with 
differently shaped spines, some of which are many rayed, stellate, 
with elavate arms. 1 Genus. 
Fam. IV. Hyalothaumadae. Sponge elongate, free, wider above, 
with anchoring fibres at the base. The filiform spieules united 
into bundles, which anastomose freely with each other, forming 
a solid framework. 2 (3) Genera. 
Fam. V. Macandrewiadae. Sponge massive or expanded, fixed, fan- 
shaped or cup-shaped. Skeleton very irregularly reticulated, with 
roundish openings. 2 Genera. 
Fam. VI. Farreadae. Sponge expanded or tubular. Skeleton nearly 
resularly reticulated, with four-sided openings. 2 Genera. 
Fam. VII. Daetylocalycidae. Sponge massive or expanded or cup- 
shaped. Skeleton more or less regularly reticulated, with angular 
openines diverging from the centre. 4 Genera. 
Fam. VII. Aphrocallistidae. Sponge tubular; tube closed with a 
netted lid or a rounded end. Skeleton more or less regularly 
netted with angular openings. 1 Genus. 
Fam. IX. Corbitellidae. Sponge tubular, attached, without any anchoring 
filaments at the base. The walls formed ofirregular network or bundles 
of siliceous needle-shaped spieules loosely arranged in sheaves 
intersecting each other, and united by sarcode; spicules of skeleton 
and sarcode hexaradiate, free from one another. 3 Genera. 
Fam. X. Askonematidae. Sponge fixed, cup-shaped, formed of 
abundant elongate spicules, with scattered hexaradiate spines often 
denticulated on the edge of the rays; spicules with bifurcate 
end repeatedly forked, and spherical groups of elongate spicules, 
which are capped at the end. 1 Genus. 
Fam. Xi. Carteriadae. Sponge cup-shaped, formed of abundant 
netted fibres containing many fusiform spicules, with scattered 
six-rayed stellate spicules, ending in a circle of reflexed lobes; 
the rays are often abortive, producing a cylindrical axis termina- 
ting at each end in the reflexed lobe, and hence they have been 
called birotulate spines. ..... 1 Genus. 
Fam. XII. Axidae. Sponge arborescent, branched, with hexaradiate sub- 
cubical spicules, as if formed of six cubes. Placed on each side 
of a central one, and with three-rayed stellate spieules. 1 Genus. 
Order VI. Sphaerospongia. Sponge generally massive, grumose; Skeleton 
strengthened with numerous small spicules crowded into globular 
or stellate balls, and with elongate spicules terminating at the 
outer end in three recurved spines, which are simple or forked. 
Fam. I. Geodiadae, The spherical masses of spicules forming a 
thick external cerust to the Sponge. 3 Genera. 
Fam. II. Placospongiadae. Sponge branched, coral-like, with a cen- 
tral axis and a hard outer coat entirely formed of solidified sphe- 
rules of spicules. The axis and outer lamina separated from each 
otber by a layer of sarcode strengthened with bundles of spicules. 
1 Genus. 
Fam. III. Tethyadae. The tricurvate spicules extending beyond the 
outer surface of the Sponge. 1 Genus. 
Fam. IV. Donatiadae. The tricurvate spicules supporting the outer 
surface of the Sponge. 3 (enera. 
Fam. V. T’heneadae. Sponge oblong, with many exeretory pores above, 
