58 



BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



Gun Cay. 



Plate XII. Fig. 2. 



On the south point of Gun Cay a lot of loose rocks are thrown 

 up well above high-water mark. The cliffs of the southern shore are 

 eaten away, and on the western face of the cay the rocks up to the line 



^OLIAN ROCKS THROWN UP ABOVE HIGH-WATER MARK, GUN CAY. 



of scanty vegetation are deeply pitted and honeycombed. All along the 

 west face of Gun Cay rectangular masses of rocks are thrown up close to 

 the line of vegetation. These masses of rocks are the fragments of the 

 shores torn off from the vertical cliffs by undermining, and then thrown 

 up by the action of the heavy seas or hurricanes. Picket Rocks derive 

 their name from such a mass of angular rocks thrown up on the very 

 crest of the ridge of the cay, looking a little way off like an irregular 

 picket fence. Holm Cay is another island of similar character, but 

 smaller. 



Running paranel with the line of outer rocks which make the extension 

 of Gun Cay to the north, we crossed magnificent banks and patches of 

 corals, some of which run close up to Gun Cay, as well as to the rocks 

 in the vicinity. Off the little sandy reach inside of the north end of 

 Gun Cay we brought up large masses of Thalassia in the dredge. 



On the east face of Gun Cay the shore rocks are so eaten away as to 

 form numerous caverns and cavities in the face of the shore line. 



