800 REPORT—1890. 
Rh. serrata is very abundant. The pink rock contains Rh. Bouchardit, W. Moore, 
and in the conglomerate beds masses of .A. difrons in a pinky-brown ferruginous 
rock were the common fossils, but there were large worn specimens of A, serpentinus, 
and also in a creamy rock A. crassus ; the brown and white stones have a Rhyncho- 
nella, somewhat like Rh. jurensis Quenst. ; the brown rock contained A. thouarsensis 
d’Orb. = A. striatulus, and the white rock A. Aalensis Zieten Germanii d’Orb. 
If this last section is correctly restored it corresponds with that at [minster, 
as far as the zone of Rh. Bouchardit ; there is then wanting the serpentinus and 
the lower part of the communis zone, the fossils from which are deposited in the 
brown conglomerate bed of the age of A. bifrons, which is covered by the zones of 
A. striatulus and A. jurensis. 
The brown conglomerate rock has been confounded with the brown marlstone 
§n the blocks found on the sea-shore near Chideock, Dorset; and the fossils have 
been mixed. 
8. On the Sounds known as the ‘ Barisal Guns,’ oceurring in the Gangetic 
Delia. By T. D. ua Toucue. 
The ‘Barisal Guns’ are sounds resembling the firing of heavy cannon at a distance. 
They are heard at various points in the Delta of the Ganges and Brahmaputra, 
and in the hills to the north of it; their origin has never been satisfactorily 
explained, though many theories have been advanced to account for it. Of 
these the principal are :—(i.) The breaking of surf-rollers during the South-west 
Monsoon on the shores at the head of the Bay of Bengal; (ii.) The falling in of 
high banks along the courses of the rivers in the Delta; (i.) The firing of bombs 
by the natives at their marriage festivities; (iv.) Atmospheric electricity ; and 
(v.) Subterranean or subaqueous volcanic or seismic agencies. 
It is shown that none of these theories is entirely satisfactory, except, perhaps, 
the last ; and that a cause of the sounds may possibly be found in slight movements 
of the layers of silt, composing the Delta, over each other, as they settle down ; 
movements which may be augmented by the strains set up by the increase and 
decrease of pressure on the surface, due to the inflow and outflow of the tides along 
the river channels. 
The paper concludes with a request for information regarding similar sounds, it 
it has been observed that any such occur in other large deltas. 
9. On the so-called Ingleton Granite.1 By Tuomas Tare, F.G.S. 
Under this commercial name a rock has recently been brought into the market 
as a road-metal. 
It is quarried opposite Dale Barn, Ingleton, in the Borrowdale series, under- 
lying the Mountain Limestone, forming Twistleton Scars on the north-west and 
Raven Scars on the south-east, extending thus quite across the valley, with a sharp 
dip to the south-west, for a thickness of about 400 yards. 
This rock has been variously described by previous observers before the applica- 
tion of the microscope to its interpretation. It is a greyish-green quartzose 
voleanic tuff. No lapilli or any included fragments conspicuously exceeding the 
average are present. This marked uniformity in texture at each horizon—graduat- 
ing from grains one-eighth of an inch down to the finest particles—points to the 
sorting action of gravity exerted upon materials in aqueous suspension. By the 
parallelism of the longer axes and the stratification arising therefrom, sedimentation 
is further in evidence. 
The detritus of a quartzite has supplied most of the clastic elements; next to 
this come crystals of quartz and of felspars, both orthoclase and plagioclase, the 
latter being the more abundant relatively, in the finer-erained layers. Ancient 
lavas, both acidic and basic—devitrified spherulitic rhyolites and augite andesites— 
have contributed of their spoils. While the majority of the components have 
! For full Report see Proc. of Yorks. Geol. and Polytech. Soc. vol. xi. (1891). 
