A. EF. Verrill— The Bermuda Islands; Geology. 47 
Part V.—THE CorRAL REEFS; CHARACTERISTIC LIFE OF THE REEFS. 
29. Reef Corals and allied forms. 
A. Corals. B, Actinians. C. Gorgonians. D. Millepores. 
30. Other Invertebrates; Sponges ; Echinoderms; Mollusks ; Annelids; Crus- 
taceans. 
dl. Tunicates. 
32. Fishes. 
33. Algee: Fucoids ; Corallines ; Nullipores. 
I. GroLoey: 
1. Character of the Rocks. 
The geology of the Bermudas, so far as the visible structure is 
concerned, is very simple and is identical with that of the Bahamas, 
Figure 1.—The original Gurnets Head of Castle Island, showing typical eeolian 
limestone formation. On the summit are the ruins of the ancient fort (a) 
called King’s Castle; b, ruins of ancient Southampton fort. 
except that the coral reefs are of greater importance in the latter. 
The rocks in both are all limestone and the red clays resulting from 
its decomposition. 
