8 Spontj. 
XVII. 8P0NGLK, 
Tho gastral cortex is subjected to little modification, though a striking 
exception is found in TJtella , with its oxeote spicules in the gastral cortex. 
Sycyssa and Leucyssa have very exceptional skeletons, with no radiate, 
but only oxeote spicules. Leucascus apparently never had a radially 
symmetrical skeleton. 
The next two chapters treat of the histology and classification of the 
heteroccele Calcar ea , with diagnoses of the families and genera. Finally, 
the origiu and phylogeny of the group are discussed and summarised in a 
genealogical tree. 
Dendy (15) has a paper on tho anatomy and relationships of a remark- 
able calcareous Sponge, Lelapia australis. The most interesting feature 
of Lelapia is the reticulated fibrous character of its skeleton, which 
appears to have hitherto escaped observation. This character is unknown 
in any other living calcareous Sponge, while it forms the most prominent 
feature in Zittel’s fossil group, Pharetrones. Dendy, however, shows that 
this fibrous skeleton may have been derived from the more primitive 
Syconoid type. Of the spicules, the “ tuning-forks” are the most remark- 
able, although they are of no great significance, as they are paralleled in 
some of Haeckel’s species. Its canal system belongs to the Leuconoid 
type, thus agreeing with Dendy’s former supposition (18) p. 180. Alto- 
gether the author thinks it unadvisable, in the present state of our know- 
ledge, to introduce the family Pharetrones into the system of recent 
Calcarea , and regards Lelapia simply as a very specialized type of the 
Grantidce. 
Hanitsch (17) gives a revision of the generic nomenclature and classi- 
fication in Bowerbank’s “British Spongiadae.” The paper consists of 
two parts, the first section giving, in two parallel columns, Bowerbank’s 
and the revised nomenclature. The second part contains the classified 
list of all British Sponges described by Bowcrbank, with their revised 
generic names. The classification is compiled from Itidley, Dendy, Top- 
sent, Sollas, von Lendenfeld, and Yosmaer. 
Horn ell (18), remarking on the colour of animals, offers an explana- 
tion why, in the case of the Calcarea } we find almost exclusively white, 
but in the Silicea a variety of colours. 
Hornell (19) gives a sketch of the structure of Sponges in general, 
and of a few species from Jersey in detail, with life-liko illustrations. 
Minchin (81) gives a critical account of the embryology of the Pori- 
fera , based upon Dolago and Maas’s recent works. 
Yon Lendenfeld (22) tells us that Suherites fruticosue , 0. Schmidt, of 
which he examined the type specimen in the Graz Museum, does not 
belong to the Suberitidce, but represents a new genus ( Tetranthella ) of 
the Lithistida. Suherites crambe , 0. S., of which he also saw the type 
specimen, is identical with S. fruticosus. Accordingly he proposes the 
name Tetranthella fruticosa. Lendenfeld considers the few chelae he 
observed in the Spouge as probably accidental. The same author (24), 
p. 189, gives a detailed description of this Sponge. 
Yon Lendenfeld (23) maintains that Placospongia is a monaxonid 
