164 bulletin: museum of comparative zoology. 



Cays and of Tyra Bank. The distance of these reefs from the shore 

 varies from one to fifteen miles. 



The small banks from which the Pearl Cays (Hydrographic Chart 

 No. 392, Admiralty Chart No. 1503) rise, which themselves rise from 

 the Mosquito Bank at depths varying from eight to twelve fathoms, are 

 fringed and covered by irregularly shaped reef patches, generally placed 

 on the eastern and northern sides of the banks adjoining the cays or 

 connecting them. Long Eeef Bank has a continuous reef on its eastern 

 edge rising from a depth of three to four fathoms. 



Great Corn Island (Hydrographic Chart No. 392, Admiralty Chart No. 

 1476), twenty-nine miles east of the Bluefield River, rises to a height 

 of three hundred and seventy feet. It is probably of volcanic origin. The 

 northern and northeastern shores of the island are protected by an ellip- 

 tical coral reef forming a great curve at a distance of about a mile from 

 the shore, with numerous heads and patches between the outer reef and the 

 shore. Off the island the bank has a depth of from thirteen to twenty 

 fathoms, the reef rising from a depth of four to six fathoms. Off Little 

 Corn Island there is a similar reef, about a quarter to half a mile from 

 the shore, with two to three fathoms upon it, which skirts the eastern 

 and northern face of the island. Great Corn and Little Corn Islands are 

 seventeen or eighteen miles from the 100 fathom line, the bank sloping 

 seaward very gradually from twenty or thirty fathoms. 



Upon the eastern half of the Mosquito Bank, between the Corn Isl- 

 ands and the cluster of reefs and banks to the south of Edinburgh Reef, 

 there are a few isolated patches of coral in from six to ten fathoms. 

 The Mosquito Shoals and the Morrison Cay Bank are the centre of an 

 extensive area of rocky heads and of coral patches south of Edinburgh 

 Channel. Both banks are skirted by an irregular undulating line of 

 reefs. Edinburgh Reef is crescent-shaped, convex to the east, rising 

 from thirteen fathoms, with fourteen fathoms to the westward of the reef 

 (Hydrographic Chart No. 945). North of Edinburgh Reef there is also 

 a cluster of small isolated coral patches and banks, of which the most 

 prominent are the Main Cape Bank, the Half-Moon Reef and Cays, and > 

 the Alargate Bank. 



The Mosquito Bank extends as a narrow belt varying from four to forty 

 miles along 'the north shore of Honduras from Patook Point to the Gulf 

 of Honduras. That part of the bank is free of shoals, with the exception 

 of a few patches to the east of Cape Honduras. On the outer edge of the 

 bank, to the eastward of Truxillo, twenty miles from the coast, is Utilla 

 Island. Utilla with the cays and islets at its western end may be con- 



