liO AUSTRALASIAN ANTARCTIC EXPEDITION. 
We must therefore regard them as older, perhaps much older, stages of 
development than the smaller ones. 
I will deal with the two groups separately. 
Group A.—The Macquarie Island Form. 
Masses of densely aggregated, small, brown, horny tubes set side by side 
horizontally, with the free ends curving away from the main axis, were obtained from 
rock scrapings, and from the under-side of stones at low water, at the North end of the 
Island. The free end of the tube is thinner and has sand grains adherent to it. 
The contained worm, removed from one such tube, has a total length of 35 mm., 
of which the gill-plume occupies about 5.6 mm.; the body is 2.5 mm. in width, and 
contains 65 segments. 
The gills are speckled with red-brown dots and splashes, closely set along the inner 
side of the filaments, the shaft being unpigmented. The filaments are loose and curl 
outwards; I find 15-20 filaments on each side. There is no inter-filamentary membrane. 
Eggs were attached to the gills, as has been stated by other writers. The thorax 
in these small forms contains usually 8 segments; though sometimes only 7. 
Group B.—Ccnmnonwealth Bay Forms. 
Of these I have seventy-two specimens, some still within their tubes, others 
have been removed therefrom before preservation. 
The tubes are of tough parchment-like material of a yellow-brown colour; but 
those from greater depths, 110-120 fathoms, are more darkly coloured, and are rather 
olive-brown. 
The longest tube measured came from 25 fathoms; it attains a length of 400 mm. 
with a diameter of 8 mm.; the surface is smooth, the upper end thinner, flexible, and 
paler in tint. It has some sand grains adherent to it. 
Another tube from the same haul is much paler in tint, and much slenderer than 
the majority; measures 90 mm. by 1.5 mm. 
Still another tube is 270 mm. long, and contains a worm measuring 226 mm. 
inclusive of the gills, which account for 44 mm. 
A worm of 150 mm. exclusive of the gills, which are 40 mm. long, contains 190 
segments. Its breadth at the collar is 6 mm.; its greatest breadth is 8 mm., and the 
height of the body 5 mm. 
I measured a number of these worms from various depths in order to see whether 
there was any correlation between size and depth, but I find none. 
