36 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



bank, the less numerous they became. The same was the case also 

 when we crossed the bank from Nassau to the Glass Window; the 

 patches of Gorgonians were more numerous as long as we kept in the 

 vicinity of the line of cays extending from New. Providence toward 

 the Fleeniing Channel. 



On reaching the so called Middle Ground (Plate X. Fig. 2), we came 

 upon a mass of Gorgonians and coral heads, through which our pilot 

 picked his way by sight. This stretch of coral and Gorgonia ground 

 did not extend far ; we soon passed out of it and were back again upon 

 the usual sand bottom, nearly bare of animal and vegetable life, with 

 only an occasional patch of corals or Gorgonians. We next came upon 

 the line of cays extending south of the Ship Channel, and were in plain 

 sight of the seolian hills and cliffs of Saddle Cay and Norman Cay. The 

 bank as we go south continues bare of animal life, no patches even of 

 Gorgonians or clusters of heads of coral to be seen in any direction. Later 

 we could see the vertical faces so characteristic of the western sides of the 

 cays in the vicinity of Conch Cut, and to the south of that the eeolian 

 hills belonging to the chain of cays to the north of Harvey Cay. 



Coming upon Harvey Cay, Bitter Guana Cay, and Great Guana Cay 

 from the west, we were able to form an excellent idea of the character 

 of the shores of the larger cays which are somewhat protected from the 

 action of the trade wind swells. Their structure is the more striking 

 in contrast with the outlying small low and water-worn cays which char- 

 acterize Conch Cut and Rudder Cut. These low islets are mere ledges 

 of rocks rising but a few feet above the water line, and likely to stand 

 but a comparatively short time as a barrier to the inroads of the sea 

 upon the larger inner cays. 



Harvey Cay is itself greatly disintegrated ; it is attacked by the spray 

 and rain. There is but little vegetation upon it, and the limit of action 

 of the sea upon its eastern face is very plain, at many places bare rocks 

 extending close to the top of the cay. The east face of the cay is pitted 

 from the action of the sea as far as it can reach. The cliffs of the lee 

 shore are full of cavities and caverns, which have been exposed by the 

 gradual inroads of the sea on the base of the seolian hills. As we steamed 

 south, we could see the breakers throwing the sea over many of the 

 smaller outer islets, or dashing its spray high above the summits of 

 the high cays of the outer chain on the eastern edge of the bank. On 

 Harvey Cay a little wild sisal grows ; the more sheltered parts are 

 covered with hard-wood shrubs, and the ordinary plants are found near 

 the shore line. The bottom where we anchored was composed of a 



