Outlines of the Bermudas. — Fewkes. 89 
The general form of the component members of the Bermu- 
da islands is such that one is immediately reminded, when 
studying a map of them, of the characteristic ring-shaped 
coral formations of the Pacific ocean, which are known as 
atolls. Although the group has been regarded as comparable 
with a compound atoll, or a large ring-shaped coral island 
with smaller circular lagoons along its rim, it has at least two 
marked differences from a typical coral atoll which appear 
even on a superficial study. These differences are as follows : 
1st. While very similar to an atoll in contour the land of 
Bermuda is much more elevated than that of the coral atolls 
in the Pacific. 
2nd. While ordinary atolls are rarely if ever greatly mod- 
ified by erosion everyone admits that the Bermudas have 
had their outlines very much changed by this means. 
The submarine platform of the islands is an oval bank along 
the southeastern edge of which the present land masses extend 
in a crescentic form. With the exception of the North Rocks, 
isolated elevated pinnacles on the northern boundary of the 
platform, all the land is confined to the southern and eastern 
rim. The inhabited islands enclose a number of open bodies of 
W'ater, or sounds as they are locally called, which represent 
the lagoons of the supposed compound atoll. 
Historically the first interpretation of the cause of shape of 
these peculiar lagoons was that their form is due to the grad- 
ual subsidence of the platform upon which the islands rest. 
It was thought that they illustrate in the Atlantic ocean the 
Darwinian theory of sul)sidenceto account for the ring-shaped 
islands in the Pacific ocean. This application of the theory 
has not commended itself to one or two geologists to whom it 
seems insufficient to account for the form of these islands. 
The facts which were thought to indicate subsidence and the 
undoubted evidence of erosion has led still other naturalists 
to a consolidation of the two theories, or rather the engrafting 
of one on the other, so that the workings of both are looked 
upon as indicated in the present contour of the islands. The 
present outlines of the Bermuda are thus regarded by them as 
due to subsidence assisted by erosion.' 
' Darwin stated tlie difficulties in interpreting the Bermudas as a 
compound atoll, wliicli have never, in the opinion of the author, been 
satisfactorily answered. This paper does not discuss the literature of 
the subject. 
