467 a 
tained in Mr. Lyell and Mr. Bunbury’s collections amounts to sixty, 
at least one-third of which are unknown as British—a want of agree- 
ment, Mr. Lyell observes, which may be partly ascribed to an im- 
perfect knowledge of the Silurian Fauna of both countries, and 
partly to the laws which influence the geographical distribution of 
existing animals. ‘The author does not deny, that, when the more 
ancient rocks were formed, the marine species may not have enjoyed 
a wider geographical range than now; for when coral reefs existed 
between the 50th and 70th degrees of latitude, a more uniform tem- 
perature must have prevailed than at the present day; but he con- 
tends that there are no data for imagining that the same species were 
ever universally distributed. 
A description of the igneous rocks of the fiord of Christiania is 
not within the object of this communication; but Mr. Lyell states, 
that the island of Langoen is traversed in an east and west direction 
by several dikes of greenstone, from two to three feet thick, but with- 
out dislocating the strata ; he likewise mentions, that the junction of 
the quartzose sandstone of Holmstrand with a vertical dike of felspar — 
porphyry thirty feet thick, is finely exhibited at Smorsteen. The 
same porphyry also overlies the sandstone at Engnaes. ‘The trap’of 
this district passes into a reddish granite, and the contact of the latter 
with horizontal, thin beds of Silurian limestone and shale is exposed 
to the height of fifteen feet at Sotfjeld, N.E. from Holmstrand; and 
the contact is visible on the opposite side of the fiord. At the line 
of junction the limestone is white, and the shale is converted into 
Lydian stone. No veins of granite penetrate the fossiliferous strata 
in that neighbourhood, as at some places near Christiania ; and the 
occurrence of a breccia at one point, where the limestone joins the 
plutonic rock, induced Mr. Lyell to suspect that the latter had been 
there protruded in a solid form. 
- Among the donations to the Museum announced at this meeting, 
and not connected with the papers which were read, were the follow- 
ing organic remains :— 
From Grays in Essex, presented by Mr. J. Morris. See Mag, Nat. 
Hist., vol. ix. p. 261, 1836, and N.S. vol. ii. p. 539 and p. 546, 1838. 
Psidium pusillum. Achatina acicula. 
Henslowianum. Valvata antiqua. 
— amnicum. — piscinalis. 
Cyrena trigonula. Bithynia denticulata. 
Unio pictorum. 
From Stutton in Suffolk, presented by S. V. Wood, Esq., F.G.S. 
For a notice of the remains found at Stutton, see Mr. Morris’s 
paper, Mag. Nat. Hist., Second Series, vol. 11. p. 543-544, 1838. 
Psidium amnicum. Planorbis albus. 
Cyrena trigonula. Lymnea truncatula. 
Helix pulchella. ——— palustris. 
Carychium minimum. Paludina marginata. 
Succinea amphibia. 
