112 
Records of the Geological Survey of India. [vol. v, 
slipper oyster 0. cucullata. Born, which is seen crusting every surf-beaten rook wherein 
little else save a limpet or barnacle could make good their hold. This oyster is eaten 
largely, and is generally wholesome, but as it occurs in creeks and spots where it becomes 
subjected to very unnatural conditions a little caution should he exercised, as under circum¬ 
stances it becomes, I believe, unwholesome. In places exposed to the open sea and the roll of 
the breakers, it would seem to flourish vigorously anywhere between tide marks, but in 
more sheltered spots its proper range seems to be lower, although its vitality is such that 
there seems to be no spot to which the fry can gain access, whereon they will not grow to 
maturity. As an instance of this I will mention oue case on the Arakan coast, where I noticed 
this species growing at the extreme (neap) high water level; indeed I may say above it, 
where the oyster could never have obtained two hours continuous immersion at any time, and 
that only during a few days in the month whilst for many days together it must have remained 
with its valves closed. The spot where this was noticed by me was a small island off the 
coast on its sheltered side. The rocks were sandstone and there was no shelter from the 
sea. I landed at high water (neaps), and the oysters I saw along the margin of the water 
were, it seemed to me, dead judging from that position. On knocking off one, however, with 
a hammer, I found it was alive, and on putting it into my mouth rcmai-ked that it felt un¬ 
pleasantly warm. Prom this we may draw the conclusion that in investigating a raised beech 
or littoral tract the evidence afforded by the presence of the small O. cucullata only reaches 
conclusively to demonstrate the difference between the spot raised and high water mark, 
and that without additional evidence no greater amount of elevation can he deduced there¬ 
from ; whilst the presence of the larger creek oyster in any raised deposit may be held to 
establish the olovation of the spot it occupied to the full amount of the interval between it 
and low water mark. In all accounts, therefore, wherein oysters are recorded as raised, it is 
very important to obtain specific information as to which oyster is meant, the difference 
involved in the discrimination amounting to the entire height to which the tide rises in the 
locality in question. 
Note ok a possible field of coal measures ik the Godavari District, Madras 
Presidency, hy AVilliam King, b. a., Deputy Superintendent, Geological Survey 
of India. 
About twenty miles to the westward of Rajamahindri there is a great area of 
brown and red Kamtlii sandstones, &c., which was very rapidly examined and subsequently 
described by Mr. W. T. Blanford. * One of the desiderata of this examination was to 
ascertain if any further indications of underlying coal-hearing rocks existed than those 
already known on the Godavari river, but Mr. Blanford was only successful in finding 
a small field of these, to which he refers as follows:—“In only one place was any rock 
seen which had a distinctly Bardlear character. This lies south of the village of Beda- 
nol, nearly due east of Ashraopetta, in a stream, and even in this case the rock was only 
white felspathic grit unaccompanied by shale or any other typical Damuda formation.” 
During the latter part of the working season just concluded, I have had an oppor¬ 
tunity of going more closely over so much of Mr. Blanford’s area as lies within the Goda¬ 
vari and Kistna districts, but still without having found any other locality than the 
one pointed out by him. Neither could I, here, find any trace of coal, nor is there any 
knowledge in the neighbourhood of its ever having been seen. There is yet, however, the 
possibility of a seam being found by closer search, considering that, there are in the stream 
Rec. G. S. of I., 1871, page 4, 1872, page 1. 
