The Atoll of Funafuti, Ellice group : its zoology, botany, ethnology and general structure based on collections made by Charles Hedley of the Australian Museum, Sydney, N.S.W.
Euspongia irregularis, var. Silicata, Lendenfeld.
Euspongia irregularis, var. silicata, Lendenfeld, Mon. Horny Sponges, 1889, p. 255, pl. xiii., fig. 2; pl. xxi., fig. 10.
Two examples of this species are in the collection, one in spirit the other dry. The colour of the spirit specimen is dark blackish brown externally, internally of a light salmon.
The main fibres of the skeleton are charged with foreign spicules, from the secondary and connecting fibres they appear to be absent.
On the reefs in the lagoon (ante p. 324).
Hippospongia dura, Lendenfeld.
Hippospongia dura, Lendenfeld, Mon. Horny Sponges, 1889, p. 298, pl. 17, fig 15.
There are five pieces, all of which appear to have been cut from one large specimen. The sponge evidently formed a cake-shaped mass; it consists of stout lamellæ joined at various points, both vertically and at the surface, with a number of subcylindrical or long, narrow meandering lacunæ between.
The dermal membrane is continued over the whole surface of the sponge. Groups of from 20 to 30 oscula pores occur in the membrane overlying the lacunæ, the pores vary in shape from round to oval, and are from 1 to 3 mm. in diameter.
Isolated reticulate patches, with small inhalent pores, exist on the elevated parts of the surface chiefly between the conuli; the rest of the surface is smooth and imperforate. The general surface is uneven and conulose; the conuli are variable in height and in their relative distance apart. They are all more or less con-nected by low intervening ridges, and usually about 3 mm. high, and about the same distance from each other, especially on the marginal and elevated regions; elsewhere they are low and widely separated.
The skeleton consists of a dense network of uniform fibres, entirely free from foreign bodies; they are scarcely separable into main and secondaries, and measure from 0·015 to 0·02 mm. in diameter.
In the denser parts of the sponge the fibres are arranged in trellis-like clusters, the mesh is elongate, angular, rarely with rounded corners; the fibres at their points of union are not per-ceptably dilated, but retain their cylindrical form.
In the lagoon with Sarcophyta.
This species has hitherto only been recorded from the American coast of the North Atlantic.