8 
AU ST R AL AS I AN ANTARCTIC EXPEDITION. 
1891. The locality from which the specimens were obtained (off Tasmania) adds but 
little to our knowledge of the distribution of the species; which has hitherto been 
obtained, so far as I am aware, only in the neighbourhood of Port Phillip. 
Register Nos., Locality, dc. —VII, 1, 2, &c., off Tasmania. 
Leucosolenia spp. 
There are in the collection a few very small, simple, tubular Leucosolenias which 
I refrain from naming, as the material is insufficient to enable me to make a satisfactory 
investigation. Two of them (R.N. II, 1, 2) were in a separate tube labelled “ Calcareous 
sponges, C. Bay,*14-12-13, D. 45-50 fath/’ Another was attached to the surface of 
Leucetta antarctica (R.jST. VI), from Station XII. 
There were also small fragments of a branched, probably reticulate Leucosolenia, 
associated with the specimens of Grantia cirrata var. aurorce and Grantia tenuis from 
Station II (?). 
Leucetta Antarctica n. sp. 
(Plate I, figs. 2, 7.) 
The single specimen in the collection (fig. 2) is an irregularly turbinate sponge, 
broadest above, where there is a large, irregular depression (not shown in the figure), 
making the sponge almost cup-shaped, and narrowing below to a short stalk. The 
cup-shaped depression is probably not a normal character, and may be due to inhibition 
of growth by a mass of Polyzoa attached to the surface of the sponge in the middle 
of the hollow. There are several large, compound vents, each consisting of a shallow 
depression bounded by a thin, prominent margin, and bearing the numerous apertures 
of the exhalant canals lying close together in its floor. These vents lie on or near the 
broadly-rounded margin of the cup-shaped depression, two of them are shown in the 
figure, and at least two others are present. The margins of all are somewhat sunk 
beneath the general level of the surface. The surface is smooth and covered by a thin 
dermal membrane, pierced by numerous small inhalant pores arranged in close-set 
groups. The total height of the specimen is 50 mm., and the maximum breadth 55 mm. 
The colour in spirit is pale yellowish-brown, and the texture rather soft and compressible, 
but resilient. 
The ectosome is very feebly developed, being represented by the thin dermal 
membrane, and there is a thin gastral cortex surrounding the principal exhalant canals. 
The canal system is of the ordinary leuconoid type. The dermal pores lead direct 
into wide inhalant lacunae, which penetrate deeply into the choansome, and there break 
up into smaller lacunae between which the flagellate chambers are thickly scattered in 
the feebly-developed mesoglcea. The flagellate chambers are much distorted by 
Commonwealth Bay. 
