AGASSIZ: BAHAMAS. 147 



broad continental shelf formed by the 100 fathom line outside of Tobago 

 and Blanca Islands, we find the bank to extend from Bequia in a south- 

 westerly direction, forming a curved elongated plateau concave towards 

 the west, with Bequia and Grenada as its principal islands, the latter 

 rising to a height of over twenty-seven hundred feet, and other volcanic 

 summits such as Carriacou, Cannouan, and a number of smaller ones 

 scarcely rising above the level of the water. Corals flourish on the 

 Atlantic face of the bank, forming fringing reefs or barrier reefs, or often 

 coral ridges connecting the smaller islets. Round St. Vincent (Hydro- 

 graphic Chart No. 1279, Admiralty Charts Nos. 791, 956), St. Lucia 

 (Hydrographic Chart No. 1261, Admiralty Charts Nos. 956, 1273), 

 Dominica (Hydrographic Chart No. 1318, Admiralty Charts Nos. 697, 

 956), and Martinique the 100 fathom line forms comparatively small 

 banks. Only a narrow belt on the northern and western face of St. 

 Vincent and St. Lucia, and a somewhat wider plateau on the eastern 

 face of Martinique, are studded within the 20 fathom line with coral 

 reef patches existing either as barrier reefs or as fringing reefs. No 

 elevated reefs have been observed on Martinique, St. Lucia, or the 

 Grenadines, while Barbados, which rises to over eleven hundred feet, 

 is surrounded with elevated reefs forming a series of terraces round the 

 island. These have been carefully studied by Harrison and J. Jukes- 

 Browne. Barbados itself is the summit of an extensive elliptical bank 

 above the 500 fathom line, the greater part extending northward nearly 

 to the' latitude of the northern extremity of St. Lucia. 



The northeast coast of Barbados (Hydrographic Chart No. 1010, Ad- 

 miralty Charts Nos. 956, 2485), is skirted by a coral reef from a quarter 

 to half a mile from shore, which encircles almost the whole island. 

 Off Palmetto Bay the reef is more than a mile offshore, but off the south- 

 east coast a bai'rier reef is found, known as Cobbler Reef, extending from 

 Kitridge Point to South Point, with a channel varying from one half to 

 three and a half fathoms, and from a quarter to half a mile in width, with 

 two to eight feet of water ; and parallel with this is a narrow sunken reef 

 with from seven to ten fathoms of water, separated from Cobbler Reef by 

 a belt of water from one quarter to three quarters of a mile wide, with 

 soundings close to the outer reef ranging from fourteen to twenty-seven 

 fathoms. To the seaward the 100 fathom line is not more than two 

 miles off. 



Grenada (Hydrographic Chart No. 1316, Admiralty Charts Nos. 956, 

 2821) attains a height of from twenty-three to twenty-seven hundred 

 feet. It is volcanic, and rises from a bank on which are the Grenadines 



