74 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



combined action of the rain and sea. Behind the shore Hne of rocks 

 extend vast flats, the pine barrens of the island. The tcolian rocks are 

 everywhere fully exposed, presenting the peculiar characteristics of the 

 great expanses of level or nearly level surfaces which in other islands 

 frequently separate parallel ranges of aiolian hills. In the sinks and 

 pot-iioles, or depressions of greater dimensions, pools and ponds, often 

 of considerable size, have accumulated, many of which are separated from 

 the sea only by the narrow wall forming the low line of aioliau hills im- 

 mediately back of the shore. 



The shores of Bahama Island, all the way from Carrion Crow Har- 

 bor to our anchorage at Turtle lieef near High Eock, have once been a 

 succession of coral sand beaches and of low clift's along the edge of the 

 low line of hills, forming a sort of dam between the pine tract levels and 

 the edge of the island. Bej'ond Turtle Reef the extension of this line of 

 hills forms a few insignificant cays to the west of Gold Rock. The reef is 

 outside of this line of cays, which represents a part of the ancient shore 

 line of Bahama Island. The reef dies out at Southwest Point, where 

 the shore is clear close np to the beach. Beyond Southwest Point, at 

 Barnard's Point, the low shore hills with vertical cliffs are again char- 

 acteristic of the shore line, the pine barren plains appearing to be from 

 one half to three quarters of a mile beliind the beach mound. "Wherever 

 there is any uutcrnp[)ing of rocks between the stretches of coral sand 

 beaches, many blocks of a'olian rock are thrown up abtive high-water 

 mark. There are a number of these rocky outcrops, and as we go 

 north past Southwest Point the sandy beaches become shorter and 

 are much more frequently interrupted by considerable lengths of out- 

 crops. Hawk's Bill Creek is an estuary which has cut Bahama Island 

 in two, and which comes out on the north side. The shore line df 

 cliffs leaves a wide opening flanked with mangroves and shrubs; in 

 the distance are the pine barrens aliout one mile inland. Soon after 

 leaving Hawk's P>ill Creek the pine l>ari-cns recede fai'ther from tlie 

 shore, and towaids tiie narrower part of the northern extremity of the 

 island the pines tliiiiinish gradually in size and in thickness, becoming 

 (juito sctittered. The low range of shore hills increases in width, ex- 

 tendiiiL,' farther inland. The continuation of the northern extrem- 

 ity (if flic island consists of fiuir or five small cays, the remains 

 or the f)rnirr northern extension of I'ahama Island. These small 

 cays are of the usual tvpe ; the rocks are a'olian, with vertical faces 

 more or less undermined, and the surface of the islets pitted and honey- 

 combed. As the })ines diminish north of Hawk's Bill Creek, their 



