96 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



extending nearly unbroken along its whole length in from three to 

 twelve fathoms of water. The reef forms a wide belt between West 

 Caicos and Providenciales, with a narrow passage of from two to five 

 fathoms of clear water between the reef and Providenciales. It skirts, 

 both as a fringing and as a barrier reef, the northern shore of Provi- 

 denciales, with but a narrow channel between the barrier reef and the 

 shore. It extends along North Caicos, at a distance varying from 

 half a mile to two miles off shore. There is a break in the reef at 

 Juniper Hole, between the North Caicos and Grand Caicos reef. The 

 latter extends nearly unbroken along the north side of Grand Caicos 

 and East Caicos to Cape Comete, and thence south along the east faces 

 of East and South Caicos. Along Long Cay the 100 fathom line is close 

 to its eastern face, from its southern extremity the reef runs in isolated 

 patches towards Ambergris Cays. "We were unable to observe its course 

 along the southern edge of the bank. The edging reef reappears again 

 about twenty miles southeast of West Sand Spit, extending all the way 

 to that point and westerly to French Cay, beyond which it forms exten- 

 sive and nearly continuous reefs along the edge of the bank, such as 

 Molasses and the Southwest Reefs east of West Caicos. 



A little to the south of French Cay we entered upon the bank, passing 

 through an opening in the edging reef, and steamed nearly east across 

 the bank, carrying from two and a half to three fathoms of water, to 

 Long Cay, passing in sight of Middleton and Six Hill Cays, and out 



SIX HILL CAY. 



into Turk's Island Passage south of South Caicos. We were in sight of 

 Ambergris Cays, beyond which are dotted the Seal Cays, running across 

 the southern part of the bank. The highest point on the islands of the 

 Caicos Bank are the hills on North Caicos and Ambergris, which are 

 said to be one hundred feet high. West Caicos is about sixty feet high. 

 North of the track we followed in crossing the bank, as the pilot in- 

 formed me, the water shallowed very rapidly, while in the direction of 

 the Seal Cays the water is deeper. 



The peculiar light green tint assumed by the western edge of the bank 

 follows the belt of the edging reef, and is in striking contrast to the white 

 bottom inside of the reef and the adjacent dark blue color of the water 

 outside of the 100 fathom line. This color, when reflected on the edge 



