1906. 
Proceedings of Irish Societies. 
37 
in the apterous insects and in Scolopendrella. The existence of these 
maxilhiUe, together with the probable origin of the gnatho-chilarium 
from two pairs of maxillce, tends to bring the segmentation of the 
diplopodan head into correspondence with that of the insectan head, 
and to prove a somewhat near relationship between millipedes and 
insects— an opinion supported by the exact correspondence in the 
number of trunk-segments between Polyxenus and a primitive insect. 
An account, with figures of the maxillae and maxillulse of Polyxenus, 
together with a general discussion on the segmentation and phylogeny 
of the Arthropoda, has recently been published by the exhibitor {Quart. 
Jou7-n. After. Scz., vol, xlix. 1905, pp. 469-492, pi. 28). 
D. M'ArdIvE exhibited fertile specimens of Cephalozia leiicantha., 
Spruce, which he collected in a plantation near the shore of Lough 
Conn, at Pontoon. Co. Mayo, in 1901. The plant is minute, fragile, and 
pellucid, bearing a remarkably large perianth for such a .small plant, 
which, like the leaves and stem, is almost white, and hence the specific 
name leticantha, " white-flowered." 
He also showed Cesia obtiisa, Lindberg, one of a curious genus of which 
we have three species in Ireland. They are often difficult to define in 
the field, on account of the upright stems with closely imbricated leaves 
and compact growth, not unlike some species of Lichen. The speci- 
mens shown were collected many years ago by the late Dr. Moore on 
Mweelrea Mountain, Co. Mayo. 
These two liverworts have a very interesting geographical distri- 
bution. In Ireland Cephalozia leucantha, so far as we are aware, has 
only been found in the extreme west of Kerry and Co. Mayo ; in 
Great Britain we have it recorded from near Portach, in Aberdeen- 
shire. Cesia obtusa was found in Co. Mayo, and, northwards, through 
the Mourne Mountains, Co. Down, and is not uncommon in North 
Wales, Laugdale in Westmoreland, and in West Inverness, Scot- 
land. Both these plants are reported m Professor Alexander Evan's 
" Notes on the Hepaticse collected in Alaska by the Harriman Expedi- 
tion," as being found there— a copy, with figures of Cephalozia leucantha 
and salient parts of Cesia ublusa, being also shown. (^Proceedings Washing- 
ton Academy of Sciences, vol. ii., 1900, pp. 287-314. Plates xvi., xvii.) 
W. F. GuNN exhibited spiral fibres from the skin of a bulb of 
Amaryllis Belladonna. In the dry investing membranes of this bulb there 
is a very extensive development of these spiral structures, which are 
placed so close together, in parallel rows, as to constitute a complete 
" coat," and as the number of layers is considerable they provide a very 
efficient protection against evaporation. In its native country the 
plant is subjected to an extreme of dry heat during its resting period, 
and the manner in which these spiral fibres, which usually serve as 
strengthening structures, have been combined and made to serve as 
protecting coverings, forms an interesting example of the adaptation of 
an organ to a function quite different from that with which it is usually 
associated. 
