162 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



than forty to fifty feet in height. It is sandy, with rocky ledges sepa- 

 rating the beaches. It is separated fi'om the mainland by deep straits. 

 From the northern end of the island a sand bank exteuds eleven miles. 

 The west side has deep water close to the shore. 



Espiritu Santo and Ascension Bays (Hydrograpliic Charts Nos. 402, 

 1380, Admiralty Chart No. 1795) are both protected by narrow reefs 

 extending across the ■ mouth of the harbors. These reefs rise from a 

 depth of from four to six fathoms. 



The Reefs and Banks of British Honduras. 



The extensive barrier reef running along the edge of the Honduras 

 Bank reaches from Ambergris Cay to the southern part of the Gulf of 

 Honduras, and forms a broad stretch of reef building patches separated 

 from the coast by a wide channel parallel with it and carrying from ten 

 to twenty fathoms. It resembles, on a much smaller scale, the great 

 Austi'alian barrier reef The Honduras Reef rises in from six to seven 

 fathoms, and the depth gradually' increases as we go westward towards 

 the deeper parts of the channel which form the inland sea separated from 

 the Caribbean by the wide baiTier reef composed of numerous detached 

 patches and cays. The reef varies in width from one or one and a half 

 miles at the southern end to sixteen and even twenty miles in the latitude 

 of Gladden Spit, where the channel is divided by an irregular area of 

 banks, cays, and patches of coral heads, with many narrow but deep veins 

 of water between them. These banks are often awash, or rise from six 

 to seven fothoms, and carry fi-om one and a half to three fathoms. One 

 of the channels leading across the bank, the English Cay Channel, carries 

 more than twenty fathoms. The principal passages through the reef 

 carry from four to six fathoms, and rapidly open into the deeper water 

 leading to the main inside channel. Chetumal Bay and the adjoining 

 territory to the north and east seem to indicate the manner in which the 

 cays and barrier reef of Honduras have been formed. The outer sea 

 face, as well as the inner eastern line of the bay, is edged by a reef. If 

 a general subsidence or erosion of the Honduras coast is going on, that 

 part of it must soon be changed into a bank like the banks flank- 

 ing the present coast, or into something similar to the barrier reef near 

 Point Gladden, the small banks and cays indicating the position of the 

 former low ranges of hills and valleys such as we find on the lowlands 

 to the east of Chetumal Bay. Subsidence or erosion, or both, have formed 

 the outline of the bank ; coral reefs have edged it, but there is nothing 



