440 General Notes. [July, sis 
low water, at other times two; where there is one, it is broad and quite 
level, with only slight irregularities, often broken into by pools and 
short channels; where there are two, the lower, which has a varying 
height, is broad, resembling the above, and near the outer edge it rises 
into a narrow upper level, very irregular and generally covered with 
barnacles, These two series graduate into one another. The outer 
edge of the reef, after rather a rapid descent from the higher levels, 
descends gradually under the water, but the sea has been so rough the 
past month as to prevent an examination far down. The inner edge is — 
quite abrupt, descending thus to the bottom, and generally has numerous 
outliers. The total height of the reef above the bottom inside, is only 
about seven to ten feet, and often very much less from an accumulation 
of material there. In breaking into the upper part we always find a 
simple nullipore growth, layer upon layer, and so compact and hard as 
to often break the edge of the chisel broadly off in vain endeavors. In 
the lower levels we find huge heads of Acanthastrea Braziliensis, and 
more rarely Heliastrea aperta. Siderastrea stellata is abundant, and 
generally of large size. We also find some immense growths of Mille- 
pora, but even here the Nulliporas are the most common. The outer 
coating of the reef is of a brown color and all looks alike from the dead 
encrusting nullipores. What is the life of the reef? Only a few bor 
ing animals, now and then a specimen of Symphyllia Harttii, Siderastrea 
stellata, or a small Favia in the tide or open pools. Sea-weeds are 
very abundant, and there is generally a rich nullipore growth on the 
outer edge of the reef, for a short distance above low-tide level. We 
know from the raised beaches, that the shores around the bay have all 
raised at the same time. Thus the destruction of the life. a 
seem as though the reef had been a coral one, but coming into the acuon : 
of the waves, only nullipores could grow, and not a single coral exists 
in the upper portion. The bottom inside of the reef has a thick bed of 
fragments of the same corals we mentioned above, and in addition im- 
mense numbers of the fragments of Mussa Harttii, which has not yet 
been found alive in the bay of Bahia. This deposit is more or less Con- 
solidated, and the material composing it must have been broken from the 
reef during the period of its elevation. Then probably all the mee 
ile portions were swept inward by the waves to form this a 
layer, which consists most largely of Millepora and Nullipora. The 
former must have been dead ere it was broken off, as the specimens are : 
generally covered over above with a coating of Nullipora. — R. Rati - 
BUN. . 
