344 Mr. A. Hancock on the Excavating Powers of Sponges, 
ment, the largest about ,,th of an inch in diameter. Spicula 
stout, nearly ;+,th of an inch long, shghtly and regularly 
curved, gradually tapering to a sharp point at one end, and 
with an oval swelling at the other, but not quite terminal, and 
frequently ill-defined. ‘3 
This. species inhabits red coral from the Mediterranean, and 
completely destroys it ; the interior being reduced to a few large 
irregularly angulated chambers divided by very thin walls, while 
the surface remains comparatively uninjured, showing no signs 
of the ravages within except a few circular punctures of no 
great size, and at first so small as scarcely to attract attention. 
The puncturing of the walls of the chambers is very strong 
and regular in this species, and the spicula are characteristic, 
and stouter than usual: the stems that unite the lobes are com- 
paratively few. 
C. quadrata. Pl. XV. fig. 6. 
Sponge composed of large, irregularly quadrate lobes, 4th of an 
inch wide, with the angles obtuse, connected without apparent 
order by several small, cylindrical stems passing irregularly from 
all sides, occasionally in pairs ; sometimes enlarged and flattened 
and arising from a depression in the side of the lobe: terminal 
twigs rather short, fine and linear: papille not very numerous, 
about z1,th of an inch in diameter, and placed rather far apart. 
Spicula very large and stout, measuring 7/,th of an inch in length, 
in form somewhat resembling a nine-pin; the shaft fusiform, 
swelling in the centre to an extraordmary degree, and tapering 
gradually to a fine point at one end; the other terminates in an 
exactly rounded head, very large, and distinguished from the 
shaft by a dusky shadow caused by its rotundity. 
The animal of this species when dry is of a dark brown colour, 
and may at once be recognized by the enormous development of 
the spicula, which possess the utmost brillancy, and are very 
striking objects in the microscope. The excavations are also 
characteristic; their squareness of form, and numerous orifices for 
the passage of the connecting stems arranged frequently in pairs 
and flattened, sufficiently distinguish this species. Only one or 
two individuals have occurred, and those in 77zdacna gigas. 
C. nodosa. Pi. XV. fig. 10. 
Sponge formed of a congeries of large, irregularly angulated 
lobes disposed without apparent order, each measuring jth of an- 
inch wide, and united to each other by several delicate, very 
short, cylindrical stems : terminal twigs slender, a little produced, 
cylindrical : papille not numerous, considerably apart from each 
other, the largest about 3th of an inch in diameter. Spicula 
