494 Mr. P. R. Lowe — Observations 



of the now sunken Honduran banks to Jamaica, and 

 thence throughovit the long and now disconnected ranges 

 which traverse Haiti, Puerto Rico, and the Virgin Islands; 

 and still we find it occupied by the same subdivision of the 

 genus. From the Virgins the progress southwards into the 

 Lesser Antilles of the white-wing-spotted race was stayed 

 by the deep oceanic passage known as the Anegada Channel, 



Lastly, there is a small northerly extension of the lohite- 

 iv'ing -spotted race (represented by C. saccharina) from the 

 eastern extremities of the Venezuela Cordilleras, and this race 

 inhabits the inner ring of the Lesser Antilles as far north as 

 St. Vincent. And as shewing how apparently unimportant 

 details conform to what we know of past geological periods 

 of land-elevation, it is to be noted that the arrangement of 

 the white spots on the lateral tail-feathers of C. saccharina 

 is identical with that seen in typical specimens of C luteola\ 

 pointing to the conclusion that C. saccharina is merely 

 an offset of the white-wing-spotted race inhabiting the 

 mountainous chains of Venezuela*. Thus in the study of 

 two apparently trifling characteristics in C. saccharina (viz., 

 the white wing-spots and the arrangement of the white 

 patches on the tail-feathers) we seem to have presented to 

 us yet another link in the chain of evidence relative to the 

 former connection of the Lesser Antilles with the continent 

 by means of an elevated causeway (in early Pliocene and 

 Pleistocene days). 



As regards the rest of the Lesser Antillean islands, we 

 find these occupied by the race ivithout wing-spots ; and in 

 conformity with what is known of former land-extensions 

 affecting the north-easterly parts of the continent, we may 

 presume that this race without white wing- spots, which now 



* It is interesting to note that an elevation of the Grenada bank to 

 the extent of forty fathoms would produce an island nearly 100 miles in 

 length ; also as confirming the above remarks upon C. saccharina that 

 Mr. Thomas Bland has called attention to the fact that the genera and 

 species of land molluscs which occur in the islands of St. Vincent, the 

 Grenadines, and Grenada, are mostly allied to those which are charac- 

 teristic of Venezuela (Proc. Amer. Phil. Soc. Philad. vol. xii. p. KtQ, 

 1871).— P. R.L. 



