THE GEOLOGIST. 
vioiisly imbrokcii and in tliat of strata once fanltcd but at rest, tlic pressure 
requisite to rupture or to fold them will accumulate enormously before they 
yield to it, when, after sonic slow and gradual movenu'nts, tlicy will be thrown 
up or down with a sudden movement, with or witliout flexures, as the case may 
be. Thus, by mechanical considerations, the author is led to believe that the 
ordinary nature of movements of the earth's crust must be sudden. 
2. " On an undescribed Fossil Pern from the Lower Coal-measures of Nora 
Scotia." By Dr. J. AV. Dawson, F.G.S. 
In a paper on the Lower Carboniferous rocks of British America, published 
in the 15th volume of the Geological Society's Journal. Dr. Dawson noticed 
some fragmentary plant-remains wliich he referred with some doubt, the one to 
Schizoptei-is (Brongu.), and the other to Splucreda (L. and H.) With these 
were fragments of a fern resembling Spheiiopter'u (Clydoptcris) adiaiitoides of 
Lindley and Hutton. Since 1S58 the author has received a large series of 
better-preserved specimens from Mr. C. P. Hartt ; and from these he finds that 
what he doubtfully termed the frond of Sc/iizojiteris is a flattened stipe, 
and that the leaflets which he referred to Splienopteris adiaiitoides really 
belonged to the same plant. Mr. Hartt's specimens also show that what Dr. 
Dawson thought to be Sphrcmhc were attached to the subdivisions of these 
stipes, and are the remains of fertile jiinnre, borne on the lower part of the stipe, 
as in some modern ferns. This structure is something like what obtains in 
the Cuban Aneimia adiantifolia , as pointed out to the author by Prof. Eaton, 
of Yale College. No sporangia are seen in the fossil specimens. 
Dr Dawson offers some remarks ou the difficulties of arranging this fern 
among the fossil Ct/clopterides, K^rr/fjeratliifP, and Adiantites ; and, placing it 
in the genus Ci/clop(eris, he suggests that it be recognized as a subgenus 
(Aneiyuites) with the specific name Acadica. 
The regularly striated and gracefully branching stipes, terminated by groups 
of pinnules on slender petioles, must have given to this fern a very elegant 
appearance. It attained a great size. One stipe is twenty-two inches in dia- 
meter, where it expands to unite with the stem ; and it attains a length of 
twenty-one inches before it branches. The frond must have been at least three 
feet broad. The specimens are extremely numerous at Hortou. 
The author then notices that the long slender leaves so common in the Coal- 
measures of Nova Scotia, and hitherto called Poacites, though sometimes like 
the stipes of Aneimites, are probably leaves of Cordaifes. 
On some specimens of Aneimites Acadica markings like those made by insects 
have been observed ; also a specimen of the Spirorbis carhunarius. 
3. " Ou the Sections of Strata exposed in the excavations for the South 
High-level Sewer at Dulwich ; with Notices of the Possils found there and at 
Peckham." By Charles Hickman, Esq. (Connuunicated by the Assistant- 
Secretary.) 
In the aut'imn of 18.59, open cuttings were made at Peckham, in comiexiou 
with the " Effra branch of the Great South High-level Sewer," for the " main 
di'ainage" of the metropolis south of the Thames ; and in the following spring 
a tunnel (330 yards in length) was being constructed inider the Pive-fields at 
Dulwich. The beds exposed in both sections belonged to the Woolwich and 
Heading Series" of the London Tertiaries (Prestwieh). 
Pom- shafts were sunk to facilitate the driving of the tunnel ; and the followng 
beds were exposed ; but as some of the beds are not persistent, but die out 
even with the extent of tiie tunnel, the several shafts differed as to the sections 
obtained from them. 
1. Soil, nine inches. 2. Loamy Clay (probably London Clay) ; twelve feet. 
Not in shaft No. 1 (the most easterly), nor in No. 4 (the most westerly), owing 
