THE NAUTILUS. 139 



1. Pleurodonte ingens (C. B. Ad.) is limited to the John Crow 

 Mountains in Portland (No. 1 in map). It is a mountain species. 

 The largest and most typical specimens come from Moore Town and 

 its immediate neighborhood, but living or dead specimens are to be 

 found scattered in all parts of this area amongst the limestone rocks. 



The varieties described by Prof. C. B. Adams, viz., indigna and 

 imperforata, are not local forms, but simply individual variations, 

 all three forms being occasionally found together. 



2. Pleurodonte chemnilziana (Pfr.) has a much wider range than 

 P. ingens, being scattered sparsely on the spurs of the Blue Mountain 

 range, and found more plentifully towards the eastern limits of this 

 area (No. 2). A small pale variety (which is otherwise typical), 

 occurs at Bath, in St. Thomas parish. 



3. Pleurodonte carmelita (Per.) is limited to the higher regions ol 

 the Blue Mountain range. This species seems to thrive on the shaly 

 soil, while all the other species are most plentiful in the limestone 

 regions. 



4. Pleurodonte sub acuta (Pfr.) apparently has two habitats, the 

 first on the southern slopes of the Blue Mountain range (No. 4 in 

 map), where it is sometimes found in company with both P. carme- 

 lita and P. chemnitziana. The second habitat (No. 4 A) com- 

 mences about thirty miles west, at Mount Diablo. Thence it occurs 

 plentifully on the mountains running due west to Ulster Spring, 

 where a few stragglers have been found. At present it has not been 

 found in the intermediate space (which is very poor in land shells), 

 but further search may possibly connect these two areas, or it may 

 be found that the form of each area constitutes a distinct species. 



5. Pleurodonte patina (C. B. Ad.) occupies a very large area. In 

 the extreme east of it the variety nobilis of C. B. Adams is found on 

 the slopes of Mount Diablo. A few miles west, at Cave Valley and 

 Aenon Town, the largest and most typical form of P. patina crops 

 up, and is undoubtedly the locality where Prof. Adams obtained his 

 types. It spreads west through the higher parts of St. Ann's and 

 Trelawny to Moore Town in St. James, gradually losing its most 

 distinctive characteristics, such as the concavity of the shell above 

 and below the periphery ; though retaining both the smooth surface 

 and the single small tooth. 



6. Pleurodonte oxytenes (A. D. Brown) is limited to Hanover. It 

 is a very clearly marked species, yet subject to considerable indi- 

 vidual variation. 



