BIOLOGY. 
.Spong. 7 
inhalant pores and interrupted only at the osculcs. In Chondrilla nucula 
the portions of this cuticule covering the potcs show fine transverse 
(radial) lines which perhaps are the expression of slender tubes traversing 
this cuticule in tho living sponge. 
Lendenfeld (20, 21) thinks that the recent researches on Sponge- , 
epithelia tend to demonstrate their diversity in different species. In 
& 'liberties fugax and Polymastia robusta he finds (21) a simple “ Flatten - 
epithel”; in Suberites massa thin and flat (“Platten”) cells which here 
however possess processes extending down into the interior of the sponge. 
On the surface of Phacellia weltncri (20) massive, granular pavement-cells 
with centripetal processes were met with. Somewhat similar cells, much 
blackened by osmic acid, occur in Papillella quadrata. “ Flask ’’-cells were 
observed by Lendenfeld (20) on the surface of Phyllospongia dendyi var. 
spiculifera and Stelospongia operculum. These cells are similar to tho 
“flask-shaped cells” discovered by Bidder in a horny sponge from Naples. 
The dermal cells of Phyllospongia dendyi are however not all flftsk-shaped : 
some are destitute of the neck and adhere with a broad base to the super- 
ficial plate to which they belong. All these cells have processes extending 
into the interior of the sponge. 
Large multipolar, granular cells underlie the cuticule in Vioa and 
Papillella (21). 
Tho inhalant pores of Axinyssa topsentii (21) arc surrounded by ring- 
shaped cells; these pores arc intracellular. 
In the canal- walls of many Clavulina (21) a single layer of low, flat 
(“Platten”) colls has been observed. Sometimes stouter pavement or 
cylindrical cells were met with in the canal- walls of Vioa y Astromimus and 
the oscular tubes of Papillella. 
The flagella of the collar-cells often cross in the centre of the chamber, 
being more than half as long as the diameter of the latter (21). In sections 
they sometimes appear joined to form a sort of plasmodium in the centre 
of tho chamber. In several cases processes were observed arising from the 
corners of the polygonal bases of the collar-cells and extending for some 
distance tangentially. 
Free on the surface of the canals readily stained cells were observed in 
several Clavulina (21). Some of these had a nucleus, in others a nucleus 
could not be made out. These cells might be compared to Masterman’s 
nephrocytes. 
E. Chones [cf. Title 21]. 
When Sollas made us properly acquainted with the chones in Tetrac- 
tinellids, they were supposed to be confined to that order. Lendenfeld 
then discovered them in an Australian Monaxonid and established for this 
species, in consequence of its possession of chones, the new family Solla- 
sellidce. Now (21) Lendenfeld has found well developed chones in quite 
a number of monaxonid, clavuline Sponges, so that their presence in 
that Australian species can no longer be considered as a reason suffi- 
cient for separating it from the other Monaxonids. The chones of 
Tethya are situated in the floors of the cortical cavities. Both in the 
inhalant and in the exhalant system chones are met with. Tho Tethya- 
chonos consist of an inner zono of roundish, massivo colls, a middle zone 
of radial, and an outer zone (ring) of circular spindle-cells. In Polymastia 
tho lacunco occupying the fistular processes are separated from the canals 
of the interior by membranes in each of which one or more chones aro 
situated. These chones consist chiefly of circular spindle-cells. In several 
species of Vioa and Papillella large chones were observed at the level of 
the limit between cortex and pulpa. These chones are generally simple ; 
sometimes, however, as in Vioa vastifica two or three chones are found 
