78 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



or even of large pieces, according to the conditions due to the outer line 

 of protecting reefs. The outer line of cays forms a sort of sieve through 

 which the action of the sea outside due to the prevailing winds is greatly 

 modified and tempered both upon the western face of the cays and the 

 eastern channel face of the Abacos. 



Steaming along in an easterly direction, keeping Little Ahaco to the 

 south, the island is covered with low growth, the cliffs of the eastern 

 face are not prominent, and the seolian rocks can be seen at all exposed 

 places on the sides of the cay which are bare of vegetation. 



To the eastward are seen the outline of the low rounded hills of 

 Spanish and Powell Cays, the latter about eighty feet in height, off Great 

 Abaco. South of Spanish Cay the bottom consists of very fine marl, 

 and is covered with sponges, coralline algae, Thalassia, and several species 

 of Penicillus. 



After passing the spit at the north end of Great Abaco the island 

 widens somewhat, so that we get two lines of seolian hills parallel to the 

 shore. The western range, which is the highest, is covered with low 

 vegetation. Nearer the shore the trees are taller, seemingly mastic and 

 mahogany woods, while from the south the pines come in again, and the 

 southern part of the island, which falls off rapidly to a low flat from 

 Mango Hill, is covered with a thick pine forest, which extends unbroken 

 to Eocky Point. About opposite Muujack Cay the shore seolian hills, 

 which run south from Angel Fish Point, are not more than from four to 

 six feet in height. Farther south they rise to twenty or twenty-five feet, 

 and pass into the flats upon which the pine forest extends, as we could 

 see when steaming from the Woollendean Cays on the inside of the bank 

 towards the western shore of the island. 



After Powell Cay comes the narrow line of Munjack Cay, and next 

 Green Turtle Cay, the most important settlement of the Bahamas after 

 Nassau. Seen from the west all the cays appear to be low seolian 

 hills with rounded outlines. Green Turtle Cay is a little more than 

 seventy feet in height. It is somewhat broader than any of the other 

 outer cays. There is a fine bluff of white seolian rock at the southern 

 extremity of the island. The base of the cliff is constantly eaten away 

 by the action of the sea, and supplies the material from which is derived 

 the whitish marly bottom which extends over the channel to the east of 

 Great Abaco. No Name Cay protects the anchorage of Green Turtle 

 Cay from the outside swell to the south, and Munjack and Crab Cays 

 protect it from the north. Owing to the short distance between the 

 outer cays and Great Abaco the sea in the channel acts upon its shores 

 with little force. 



