124 On the Flora and Fauna of Santa Cruz. 



The discovery of a submarine ridge, connecting Santa Crnz 

 with Saba is interesting ; but its geological age is as unc(?rtain 

 as is that of the deep chasm now separating Santa Cruz from 

 St. Thomas. 



I have shown, conclusively, I think, that the land-shells sup- 

 ply abundant evidence of the former connection of Santa Cruz 

 with St. Thomas, and the other islands of the Virgin group, but 

 none of its connection with Saba. 



A variety of B. f rater cuius occurs in Saba, and a Succlnea, 

 which I believe to be Riisei, with several of the widely distributed 

 Stenogyrce, and Helicina lyicia, Fer., belonging to the Carib- 

 bean fauna, is also found there. Very recently I have received 

 from tlience, through tlie kindness of my friend, Mr. F. A. 

 Ober, many specimens of Amjjliibulima patula, Brug., hitherto 

 known only from St. Christopher, Dominica and Marie- Galante. 



The five-hundred-fathom line mentioned, embraces Anguilla, 

 St. Martin, and St. BartholomcAv, but their land-shells are far 

 more allied to those of Porto Rico and the Virgin Islands than 

 to Caribbean species. Macroceramus signatus, Guild., occurs 

 in Anguilla and St. Bartholomew, in several of the Virgin Islands, 

 and in Hayti, — the genus is not represented in the Caribbees. 



Pineria Schrammi, Fisch., of Guadeloupe, which I believe to 

 be identical with P. Viequensis, Pfr., of Vieque and Barbados, 

 inhabits €ach of the three islands on the Anguilla bank. 



AVith regard to changes of the flora and fauna of Santa Cruz, 

 two causes have been suggested, l)ut entirely under misappre- 

 hension, and I deem it desirable to place the facts on record. 



The Rev. John P. Knox, in his " Historical Account of St. 

 Thomas, W. I." (New York, 1852), relates circumstances con- 

 nected with the establishment of a French colony in Santa Cruz, 

 in 1650. The settlement, he says, proved at once very un- 

 healthy. He adds: — "In order to arrest the mortality which 

 was so rapidly thinning their numbers, — a mortality which arose 

 from the dense and aged forests that covered the island, scarcely 

 affording an opportunity for the winds to carry off the poison- 

 ous vapors with which its morasses clogged the atmosphere, — 



