6 PROF. E. A. MINCHIN ON THE [May 2, 
The specimens of this sponge which I have studied nearly all 
came from Banyuls-sur-Mer, where this species is extremely abun- 
dant. By the kindness of Monsieur Topsent, however, I have 
seen a specimen from Roscoff, not differing in any respect from the 
Mediterranean specimens. ‘The sponge therefore has a wide range 
of distribution, and is almost certainly to be ranked as a member 
of the British Fauna, though it does not appear to be common on 
our coasts. Hanitsch has, indeed, recorded it from Liverpool : 
I have no reason to doubt the correctness of this record 
beyond the fact that my experience of specimens labelled contorta 
by the most eminent authorities has left me very sceptical as to 
the correctness of any identification of this species which I have 
not checked ; a scepticism heightened, in the present instance, by 
the fact that Hanitsch names his specimens Ascaltis contorta. I 
may add that the sponges named Ascandra contorta by Breitfuss 
in various memoirs have nothing to do with this species, and 
should not therefore be taken into account in considering its 
geographical range. 
At Banyuls-sur-Mer Clathrina contorta is not only one of the 
commonest, but also one of the largest Ascons occurring there. 
Colonies frequently measure 8 centimetres or more across. They 
consist of a massive or spreading growth of twisted anastomosing 
tubes, running in all planes, and forming a dense feltwork from 
which arise at intervals the short, straight, not very conspicuous 
oscular tubes, which reach two or three millimetres in height, 
and are of slightly larger calibre than the body-tubes, as the basal 
growth may be called. The body-tubes are centred round the 
oscular tubes more or less distinctly, and in the region of the 
oscular tube the basal system of tubes is usually slightly raised up 
to form a conulus bearing the oscular tube on its summit; but 
these conuli are generally very shallow, so that the upper surface 
of the spreading colony is nearly flat, not lobulated like that of 
cerebrum, nor cushion-like, as in reticulwm—two species occurring 
commonly with contorta, but both very easily distinguished from it 
at sight. Photographs will make the external characters of contorta 
clearer than any description (Plate I.). Of its allies, it is perhaps 
coriacea with which contorta might be most easily confused, on 
simple inspection ; the latter, however, with its greatly developed 
gastral rays, is not found contracted up, with closed oscula, like 
coriacea, and when expanded its body-wall is much thicker and 
less delicate. 
The spiculation of Clathrina contorta comprises in typical 
specimens all the three kinds of spicules found in calcareous 
sponges. 
The triradiate systems are equiangular, with the rays straight, 
tapering imperceptibly for the proximal half or two-thirds; after 
that tapering more rapidly to a sharp or moderately blunt point 
(text-fig. 2, 1a-1f). The distal extremities of the rays are often 
irregular in outline, sometimes markedly so. ‘The rays vary in 
length from 80 to 130, in different specimens, but may be said 
to average 90-100. The breadth at the proximal end of the 
