86 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



The seolian hills of the western face of the former Crooked Island land 

 were probably quite low, and were soon eateu away. As the bank sub- 

 sided, the great lagoon or flat occupying once the central part of the isl- 

 and, as at lnagua, sank below the level of the sea to become the bottom 

 of the bank, while the low land to the westward was all washed away 

 and disintegrated by the action of the sea and rains. 



We can readily trace a similar course of events on Caicos Bank, and 

 find no difficulty in reconstructing the Caicos Bank land. This is now split 

 up into West Caicos, Provideuciales, and North, Grand, and East Caicos, 

 which form the northern and northwestern outline of the bank, while 

 South Caicos, Long Cay, Ambergris Cays, and the Swimmer Rock fringe 

 the eastern face of the bank, and Molasses Reef, French Cay, and West 

 Sandspit are the remnants of the land fringing the southwest line of 

 the Caicos Bank. Here and there on the southeastern part of the bank 

 rise the Seal Cays, Pear Cay, White Cay, and the small rocks which 

 were once a part of the greater Caicos land. The bank itself, like 

 Crooked Island Bank, the Turk's Islands, in fact all the banks, not ex- 

 cepting the Great Bahama Bank, show a dip to the westward, and the 

 same is the case with the sunken Mouchoir, Silver, and JNavidad Banks. 

 Great and Little lnagua evidently have not been sul ject to the same 

 amount of subsidence which has so materially affected the islands and 

 banks to the seaward. 



In addition to these larger banks we have Mira por vos Bank with a few 

 insignificant cays, Diana and Brown Banks, both of which are sunken, 

 the one with ten, the other with nine fathoms in the shallowest part. 

 To the southeast of Turk's Islands are Mouchoir and Silver Banks, on 

 both of which there are rocks awash and coral heads on the northern 

 faces of the banks, with a few isolated rocks irregularly scattered, the 

 depths on their banks ranging from nine to twenty fathoms ; and finally 

 comes the last sunken bank to the eastward, Navidad Bank, with an 

 average depth of about sixteen fathoms and a least depth of eleven 

 fathoms. 



Watling Island. 



Plate IX. Fig. 12 ; Plate XXIII. 



Watling, as is seen from the chart, is twelve miles long and from five 

 to seven wide. Its shores are but slightly indented. The greater part 

 of the surface of the island is occupied by salt water lagoons of very 

 irregular outline, formed in the valleys and sinks of the cross ranges 



