2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 121 



General Description of Coast 



The island is of great relief with a high gradient to the shore. Off 

 the promotories the gradient is so steep that in some places there is 

 only a narrow belt less than 100 feet wide with depths of less than 85 

 feet. The lowest gradients were in some of the sandy bays such as 

 that at Mero, where a depth greater than 85 feet was not encountered 

 within a half mile of the shore. Two main types of environments were 

 apparent on the Caribbean side of the island: the rocky-coral areas 

 and the sand areas. 



Rocky -Coral Environment ' 



Off the promontories the bottom is generally rocky with many corals ! 



and sponges (fig. 1; pi. 1: fig. 1). Small sandy patches of approxi- | 



mately 100 square feet occur within this rock-coral. Usually this | 



ROCKY-CORAL ENVIRONMENT | 



Echinomeiro lucunter (Linnoeusl 

 Diodemo ontillorum Philippi 

 Tripneusies ventncosus tLomorck) 

 EuCidons tribuioides (Lomorckl 



Clypeosler rosoceus (Linnoeusl 

 Clypeosier subdepressus (Gro/l 

 Meomo v«nlricosa ILomorck) 



in sondy potches — down 



10 85 fi 

 Diodemo oniillorum Philippi 



down 10 85 ft. 



Corel, sponges 

 encrusli 



Schiiosler (Pomstet) 



floridiensis Kier and 



GronI 



Figure 1 



rocky-coral area continues down to approximately 75 feet, where the 

 rock ceases, and sand continues downward at a steep grade. Al- 

 though some of the coral masses are large, most of them are not very 

 thick and barely cover the rocky substrate. The crinoid Comadinia 

 echinoptera (Muller) lives commonly in crevices (pi. 1: fig. 1) in the 

 coral from depths of 15-85 feet and probably deeper. 



In the shallow water of the rocky-coral areas, from low tide to 10 

 feet, the most common echinoid is Diadema antUlarum Philippi (pi. 2: 

 figs. 4, 5) except in areas of strong current, where Echinometra lucunter 

 (Linnaeus) is more abundant. I saw a few specimens of Eucidaris 



