1911.] natural sciences of philadelphia. 577 



2. Notes on the Mollusca of the Kingston Region. 



Collections in the vicinity of Kingston were made at Rockfort, on 

 the slopes of Long Mountain; near Constant Spring; at Stony Hill — 

 all in the parish of St. Andrew. Rockfort and Constant Spring are 

 easily reached by trolley from the centre of Kingston; Stony Hill is 

 within eas}' walking distance from the end of the trolley line at Con- 

 stant Spring or it may be reached by driving from the same point. 



The Rockfort station is at the base and on the slope of Long 

 Mountain, a hill which divides the Liguanea plain in which Kingston 

 lies from the valley of Hope River. The collections were made near 

 the quarry in the soft limestone that is located near the old fort; also 

 on the raised beaches and the lower slope of the hill. The hillside is 

 grown up in "bush," lignum vitse, logwood, tree cactus, "wild pines," 

 or species of the Bromeliacece, and various thorny shrubs make 

 progress through the thickets rather slow. The raised beach is some 

 20 or 30 feet above the present water level in the bay and is covered 

 with fragments of limestone mixed with recent marine shells. It is 

 wooded like the rest of the hillside and is very porous and dry. 



Ascending the hill slope, the surface becomes covered by loose 

 pieces of the limestone and is even more dry than the raised beach. 

 When this locality was visited in the previous March, during the dry 

 season, very few living mollusks were seen except the arboreal Oxy- 

 styla undata jamaicensis Pils., which was observed on the tree cactus 

 as well as in the branches of the other trees and shrubs growing near 

 Rockfort Garden, and Tudora armata (C. B. Ad.), which was found 

 sparingly, moving about on a damp exposure of the limestone. In 

 the summer, however, when showers are more frequent, a consider- 

 able number of the species were taken alive. The prevailing char- 

 acteristic of this Rockfort station is its general dryness throughout 

 most of the year. 



The plateau of limestone rock which forms the high land in the 

 centre of the island, as at Mandeville, extends to the east as far as 

 Constant Spring, where it abuts against the older rocks of the Blue 

 Mountain. Certain spurs of this plateau, reaching out to the north- 

 east, form by their dissection isolated limestone hills, rising from the 

 Liguanea plain. These are near the hotel at Constant Spring, and 

 from some of these little isolated hills the species recorded as from 

 Constant Spring were obtained. The main mass of one of these 

 spurs, rising rather steeply from the Constant Spring level to an 

 elevation of 1,000 feet, becomes the hill marked on the maps as 

 Stony Hill, and the same name has been given to the small village 



