42 
President's Address. 
[Feb. 
found, but a series of sedimentary beds occur, long since classed and de¬ 
scribed by Mr. H. B. Medlicott, in descending sequence, as Krol, Infra-Krol, 
Blaini, and Infra-Blaini. With these sedimentary beds gneiss is associated, 
and two difficulties have hitherto attended all attempts at determining the 
position and relations of the Simla rocks; the first being that the sedimen¬ 
tary beds, in places, appear to be distinctly lower in position than the 
gneiss, and the second that no clear connexion can be traced between the 
sedimentary unfossiliferous beds to the south of the snowy range, and the 
fossiliferous series to the north. Stoliczka considered that the gneiss of 
Simla was newer than the central gneiss, and that the Krol limestone, the 
most characteristic bed of the Simla area, represented the Lilang triassic 
limestone of Spiti. Mr. Lydekker suggested on the other hand that the 
Krol limestone was probably the same as that of the Pir Panjal, and conse¬ 
quently carboniferous. Col. McMahon confirms Stoliczka’s views as to the 
resemblance between the Krol and Lilang limestones, but has shewn, on 
what appears to be clear evidence, that the gneiss of Simla and the ‘ Central 
Gneiss’ are identical, and that the apparent superposition of the gneissic 
rocks on the sedimentary series near Simla is due to the original deposition 
of the latter in valleys or other hollows worn out of the surface of the 
former, and to the subsequent great compression of ' the whole area, and 
partial metamorphism of the sedimentary rocks. These views, worked out 
with much care, suggest a similar explanation of those singularly anoma¬ 
lous sections in Sikkim in which, as Mr. Mallet has shewn, there appears, 
on all sides of the mass of hills around Darjiling, to be a gradual passage in 
an ascending section from unaltered Damuda sandstones and shales, contain¬ 
ing coal seams and fossil plants, to quartzites and slates, and from these to 
gneiss. 
Another Himalayan paper by Mr. Ball refers to the origin of Naini 
Tal and the other lakes of Kumaun. The peculiarity of these lakes is due 
chiefly to the paucity of similar accumulations of water throughout the lower 
Himalayas in general; in the higher Himalayas lakes are common enough, 
and are, in numerous cases, clearly due to glacial action. Mr. Ball considers 
that the Kumaun lakes are not of glacial origin, but caused by landslips, as 
are a few other lakes in the lower Himalayas. The question cannot, how¬ 
ever, be considered as definitely settled, for Mr. Theobald, who has recently 
examined the neighbourhood of Naini Tal, has come to a conclusion exactly 
the reverse of Mr. Ball’s. 
A subject of some interest has been discussed by Mr. Mallet in a paper 
on the ‘ mud-volcanoes’ of Raniri and Cheduba, in which he shews, on what 
appears to me to be unanswerable evidence, that nothing resembling igneous 
volcanic action has been exhibited by these vents, and that they are due to 
the evolution of gaseous hydrocarbons, accompanied by water and small 
