The third section does not concern us, and need not be further 
referred to. 
Now, it will be at once seen that the characters of the peristome 
as displayed in var. solidus will tend to place this shell in the first 
rather than the second section, which is strengthened by the fact 
that living examples collected by myself and Colleagues do show a 
tendency to a twisting of the columella. 
Equally remarkable is the affinity of P. bivaricosus var. solidus 
with the heavy and fine fossil species P. senilis , G assies,* * * § and 
P . subsenilis , Gassies,f from New Caledonia. These are appar- 
ently a ponderous edition of the local shell P. Caledonians, enor- 
mously thickened in a similar manner to our var. solidus , only 
more so. The outwardly reflected peristome is very thick and 
laminated, the outer lip bearing a similar emargination to var. 
solidus . The tubercle on the callosity is equally proportionately 
larger, but there is again the difference, in the form of the anterior 
outline of the mouth, which is rounded and almost effuse rather 
than angular, and there is no anterior channel. 
My colleague, Mr. J . Brazier, to whom I am indebted for the 
loan of specimens of P. senilis , has also communicated two fossil 
Placostyli from Mare Island, Loyalty Group, collected by himself. 
These show precisely the same thickening of the shell, and in 
particular of the peristome. To me they appear to have a closer 
relation to P. caledonicus , than to either P. senilis , or the local 
species known at the Loyalty Group, P. edwarsianus,: j; although 
they have the posterior portion of the peristome inflated as in the 
last named, rather than contracted to some extent as in P. cale- 
donicus. Mr. Brazier met with this shell in the sand beds 
accompanying the coral-rock of the island at the time this was 
being quarried by Missionary Jones for use in the building of his 
Church. 
In the “Geological and Physical Structure of Lord Howe 
Island, I drew attention to facts tending on the one hand 
to prove a former union of that island with New Zealand, and on 
the other an extension northwards, and perhaps also in a north- 
easterly direction, of this same old land, chiefly deduced from 
soundings. Our knowledge of the conformation and physical 
features of land formerly existing in the S^uth Pacific is but in 
its infancy, and it will be particularly interesting to ascertain in 
the future, if other portions of the fauna of either New Caledonia 
or the Loyalty Islands, confirm the indication of this land extension 
and continuity in their direction also. It must not be forgotten 
* Faune Conchyl. Terr, et Fluvio-lac. Nouv.-Caledonie, 1871, Pt. ii., p. 
63, t. 4, f. 2. 
t Ibid, 1880, Pt. iii., p. 39, t. 2, f, 1. 
x Gassies, loc. cit ., 1871, Pt. ii., p. 63, t. 4, f. 2. 
§ Mem. Austr. Mus., No. 2, 1S89, p. 122. 
