92 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



is low, ruuning into the shallow water of the bank. Nowhere, except 

 near the southern end of Fortune Island and to the west of the Fish 

 Cays, and a small patch to the eastward of them where there are two 

 fathoms, is this shallow water of greater depth than one to one and a 

 half fathoms, and a great stretch of the bank carries even less than 

 that. 



Acklin Island and Castle Island, as seen from the southeast, pre- 

 sented no features differing in any way from those of the other Bahama 

 Islands. Vertical bluffs of aiolian rock, of greater or less height, char- 

 acterize their sea face. The trend and outline of the eeoliau hills of 

 Acklin plainly indicate their origin. 



Fortune Island is nine miles long, comma-shaped, barely a quarter of a 

 mile wide at its northern extremity. Near the south end a hill rising to 

 a hundred and ten feet slopes gradually towards it. Off the east coast 

 near the south end there is a deeper belt of water running rapidly 

 into six or seven fathoms. From the southwest end of Fortune Island 

 a narrow reef extends along the whole western face, in from four to 

 twelve or fifteen fathoms, towards the edge of the 100 fathom line 

 bank, which drops off abruptly from the outer edge of the reef. The 

 Fish Cays are the only remnants of the land once skirting the south- 

 ern part of the western edge of the bank, or perliaps of the land which 

 once covered the whole bank, and of which tlie larger islands are 

 the vanishing tops. To the eastward they are surrounded by a series 

 of sand bores which do not quite reach the surface at low water. Off 

 the west coast of Fortune Island the 100 fathom line runs close to the 

 shore, leaving but a narrow belt of soundings. This belt widens out 

 somewhat about half-way north along the west shore, and from that 

 point an irregular coral reef extends, in from three to five fathoms, 

 almost to the northern end of Crooked Island. The western end 

 of Crooked Island is cut up by narrow lagoons opening on the bank 

 side. The inner one opens by two channels edged with mangroves into 

 a large inland bay nearly ten miles across. The outer one is separated 

 from the Crooked Island passage by a narrow band of recent coral sand. 

 This gradually disappears as one goes farther on the bank, until finally 

 the bottom is made up of the debris of aiolian rocks mixed with frag- 

 ments of shells, and other Invertebi'ates, the whole kept more or less in 

 place by the numerous calcareous algse which flourish on the limestone 

 bottom. 



On entering the bank off the southern extremity of Fortune Island 

 we found the bottom to be dotted with coralline akw, fine sand, and 



