482 
PROTOZOA. 
openings of the coelenteric cavities of the sponge-body. The 
Holosarcince correspond to O. Schmidt^s hypothetical group of 
Protosponyice ; but the difference in the structure of the sponge- 
body is not sufficient to separate Schmidt's Halisarcina, Gum- 
minecB, and Ceraosponyice from the siliceous sponges. Ehlers 
lays most stress on whether the texture of the sponge is capable 
of secreting spicules or not. He would introduce a section 
Alithosponyice in the Protosponyite, making the Stromatopores 
a separate group in it, called Ptychosponyia^ and characterized 
by their lamellated structure. The Myccosponyice and Cerao- 
sponyice will also be placed here, though exhibiting a somewhat 
higher phase of structure. He thinks Hackel is wrong in 
making these latter groups into wddely distinct sections as Silici- 
sponyice and Calcisponyice. Remarks on the position of various 
sponges, and on the structure of the calcareous sponges, con- 
clude the paper. 
H. J. Carter, '^On two undescribed [marine] Sponges and 
two Esperiadce from the West Indies; also on the Nomencla- 
ture of the Calcisponge Clathrina, Gray," Ann. N. H. (4) vii. 
pp. 268-283, pi. 17, redescribes and figures Ectyon sparsus, 
Gray (=Chalinopsis clathi'odes, Schmidt), and Acarnus innomi- 
natusy Gray. He proposes the following primary division of the 
Sponyiadce: — (1) The rigidity of the skeleton dependent on a 
predominance of the sarcodal over the siliceous element : com- 
mencing with Veronyia, Bowerb., in which there is nothing but 
horny fibre. (2) The rigidity of the skeleton dependent on a 
predominance of the siliceous over the sarcodal element : ex, 
yr. Dactylocalyx puniceuSy Stutchbury, in which the horny fibre 
is silicified. (3) The rigidity of the skeleton dependent on a 
predominance of the spiculous over the sarcodal element : ex, 
yr, Acarnus innominatuSy in which the sarcodal element is re- 
duced to a minimum ; HyalonemUy &c. ; also the Calcisponyice. 
This division cannot, however, be maintained if the presence of 
the tricurvate or bow-like spicule is made supreme. Sponyia 
(Graniid) coriaceUy Montagu & Johnston, = G. clathruSy Schmidt, 
= Clathrina sulphur eUy Gray, is also noticed. The colour of a 
sponge may sometimes be due to the presence of a parasite, as 
in a specimen of Halichondria inci'ustansy the tips of the surface 
of which are a beautiful carmine-red, owing to an algal (?) 
parasite. 
Perty remarks popularly on the classification of the sponges, Mitth. Ges. 
Bern, 1870, pp. xix-xxv. 
H. James-Clark considers that the close relationship between the hiftc- 
soria Flagellata and the Sponyice Ciliatce is proved by the discovery of the in- 
termediate Phalandcrkmi, Oienk. Am. J. Sc. (3) i. pp. 113, 114, ii. pp. 426- 
436 ; Ann. N. H. (4) vii. pp. 247, 248. 
IT. J. Carter (Ann. N. II. (4) viii. pp. 1-27, and plates 1 & 2, represent- 
