1910.] 



NATURAL SCIENCES OF PHILADELPHIA. 



511 



them to the 110 species enumerated below gives a total of 127 species 

 of land snails for Mandeville and its environs. To this number, 

 considerable additions may yet be made, chiefly among the very small 

 species. 



The tertiary limestones underly the region about Mandeville, exposed 

 in nearly every roadside cut and in many small borrow-pits along the 

 post-roads, and generally cropping out on every hill-top. On the 

 slopes of the steeper hills the limestone often stands up in bold cliffs, 

 especially on the higher hills of the northwest and west of the town, 



KendaJ- 



Fig. 1. — Sketch map of Mandeville and environs. 



in the ridges towards the western border of the Parish of Manchester. 

 The elevations run from about 1000 feet above sea level at Williams- 

 field to 2060 at Mandeville and 2700 on the ridge overlooking the 

 valley of St. Elizabeth Parish and Black River. The entire country 

 was evidently once covered with jungle or "bush" throughout, but 

 in the more cultivated parts the ground has been cleared of woods 

 except on the tops of the stony hills. 



There are no streams or other surface water in this part of Man- 

 33 



