sponqiidj:. 
8 Spong, 
Italian dredging expedition in G23-1600 mdtres, off Sardinia; H. H. 
Giglioli, Nature, xxiv. p. 382. 
CALCAKEA, 
VosMAER (15) discusses the homologies of the canal system in different 
groups, illustrating his views by diagrammatic figures, pi. iv. He considers 
the whole /S^/cow-Sponge, and not merely the individual radial tube, to be 
homologous with the A scon form. The inter-canals of Sycon probably 
represent the pit-canals of Ascon. The Leucones have probably arisen 
from the Sycones by production of lateral coeca from the radial tubes, 
and limitation of the collar-cells to small tracts of the canal system. 
Vosmaer associates the Leucones with non-calcareous Sponges in the 
relations of its canal-system. 
Clathrina coriacea, recorded from South-west Chili by Ridley (12), 
and from south coast of Franz- Josef Land, id. Ann. N. H. (5) viii. p. 455. 
Leucandra aspera (15), p. 145, pi. iii. Vosmaer’s study of this form 
demonstrates the existence of an extensive inhalent canal-system leading 
from the pores by wide vessels to the ciliated chambers, into which these 
canals open by small pores. The chambers are grouped round largo 
excretory canals, into which they open directly by wide openings. Throe 
body-layers of different characters make up the Sponge. The middle 
layer is a true connective tissue, consisting of nucleated, fusiform or stel- 
late cells, embedded in an abundant ground-substance ; the fusiform cells 
are the most abundant, but are small. The spicules have distinct sheaths. 
Leucandra caminus — Aphroceras, (12) p. 155, from off South-east 
Brazil ; a new var., crassior, described from the same locality. 
Lacinia stellijica, Selenka, (5) p. 249 ; its Sponge nature requires con- 
firmation, in Carter’s view. 
New Genera and Species. 
CARNOSA. 
Oscariay Vosmaer, (15) p. 163, note. Formed to contain Halisarca 
lohularis, as differing from II. dujardini in the ciliated chambers being 
connected with the excretory canals by fine tubules, instead of opening 
directly into them. 
Halisarca cruenta, Carter, (5) p. 247. Laminar, spreading on sea- 
bottom, Gulf of Suez ; no fibrous structure. 
Halisarca bassangustiarum, Carter, (2) p. 373, described with doubt, 
Bass’s Straits. 
CERATOSA. 
Aplysina purpurea^ Carter, (3) p. 108, Freemantle, Australia ; com- 
pacta^ id. 1. c. p. 109, South-west Australia; capensis, id. 1. c. p. 110, Port 
Elizabeth, Cape of Good Hope. 
