187].] 5^ [Eland. 



Considering the facts of distribution already given, and the above 

 mentioned soundings, it seems highly probable that very deep water \\ill 

 be found between the Anguilla and Antigua banks. 



In this connection it is interesting to notice that the depth of the sea is 

 1,376 fathoms (8,256 feet) between Cuba and Jamaica, in X. Lat. 18^ 36', 

 W. Long. 76^ 03', a somewhat near approximation to the Latitude of the 

 great depth between the Virgin bank (St. Thomas) and Saba. 



The fauna of St. Croix is closely allied to that of Puerto Rico, and seeing 

 the depth of water between them, it is a significant fact that Garacolla, 

 {Helix'), caracoUa L. one of the characteristic species of the latter, is 

 found subfossil only, with other extinct species, and among them a StropMa, 

 in the former. Meg ale ma stoma, Alcadia, and Macroceramus do not exist 

 in St. Croix, while there is one species of Cylindrella. With further 

 reference to the soundings, the Latitude of Jamaica, and the nature of 

 the fauna of St. Croix, I should mention that M egalomaMoma and StropMa 

 have none, and Macroceramus one representative (a Cuban species) in 

 Jamaica, in which Island there are, however, 14 species of Alcadia and 

 51 of Cylindrella. Sombrero has one living species {CJiondropoma Julieni 

 Pf.) which is also found, with a StropMa, embedded in the phosphatic 

 limestones of that Island. 



Professor Cope lately referred to me, for determination, shells from the 

 matrix between the femoral condyles of Loxomylus latidens, Cope, one of 

 the great extinct Rodents, the bones of which have been found in the 

 caves of Anguilla. The shells are closely allied to Tudora pupaeformis, 

 Sow, now living on Anguilla, and apparently identical with an unde- 

 termined species which inhabits St. Martin. 



Sectiox T. — Subdivision 1. Islands on tlie St. Chrisioplier and Antigua 

 hanks, Jloniserrat, Guadeloupe, Dominica, Martinique, and Barbados^. 



Subdivision 2. St. Lucia, St. Vincent, Grenada and the Grenadines, To- 

 bago, and Trinidad. 



In former papers I did not treat the fauna of the Islands in this section 

 as capable of subdivision, but with my present increased knowledge must 

 necessarily do so. 



Immediately to the south of the Anguilla bank there is, to the eastward, 

 a bank on which stand Barbuda and Antigua, and to the westward, another 

 (separated from the adjacent Islands by channels of a greater depth than 

 200 fathoms, 1,200 feet), which constitutes the base of St. Eustatius, St. 

 Christopher, and Xevis. At a short distance from the northern end of 

 the latter bank stands Saba (about 2^ miles in diameter,) rising perpen- 

 dicularly from the sea to the height of 2,820 feet, with the 100 fathoms 

 (600 feet) line of soundings about half a mile from its western, and a little 

 more than half that distance from its eastern side. Late soundings between 

 St. Eustatius and Saba (Lat. 17^ 81' 10", Long. 63^ 08' 30") give a depth 

 of 343 fathoms (2,058 feet). 



* I omit mention of several small Islands geographically belongiugto those enumerated in both 

 subdivisions. 



