68 Zoological Society : — 



about half a teaspoonful of dirt, such as I have alluded to, into it. 

 Holding the tray at each end, and tilting it the furthest side dowu- 

 vavds, shaking it lightly backwards and forwards, right and left, end 

 to end, causes the dirt to fall and spead somewhat evenly along the 

 outer edge ; then, lerel/inc/ the tray, a slight jerk from side to side 

 of the tray causes the whole of the dirt to spread pretty evenly over 

 the tray's surface, and exposes every minnte object to view, with the 

 aid of strong spectacles or a lens. A pointed wetted camel' s-hair 

 brush takes up and may deposit the minute subjects into a pill-box, or 

 other recej)tacle, for fi'.ture examination. The formation of Jamaica 

 being mostly tertiary limestone, out of about a quart of such dirt as 

 this, I have taken dozens and dozens of minute specimens of no less 

 than thirty-one species, besides larger ones, which the naked eye 

 could well see — probably upwards of fifty species from one quart of 

 dirt altogether I 



I am about to describe sixty-one new species, which, added to 

 those described by Adams, make the total of eighty belonging to 

 Jamaica. Yet let it not be imagined for one moment that I consider 

 these are all that inhabit the island : on the contrary, I incline to 

 think that that number might be doubled or trebled were the whole 

 land explored. 



I consider that the range of each species is very limited, and that 

 each spot of land suitable to them will contain distinct species which 

 are not to he found elsewhere. S. pisum is a remarkable exception. 

 That shell occurs in the Back Woods or highest mountains in the 

 nijrth of Manchester; at Porus, say ten miles "crow-fly" distance 

 on the east border of jSIanchester ; at Moreland and " Bull dead " 

 in Manchester, say about the same distance south, near the western 

 border : and again it is found at Accompong Town in St. Elizabeth's 

 parish, at (say) twenty-five or thirty miles to the west. And it is 

 fin'ious to observe, that, taking Manchester back woods as the focus, 

 1 have collected and received shells from many intermediate spots 

 between it and Porus and Moreland, and Bull dead and Accompong 

 town, without getting one St. j^isutn, although many shells equal or 

 smaller in size of other genera and sj)ecies. But take any other of 

 the Stoastomidce, and probably you will search for it in vain outside of 

 a circumference of three-fourtlis of a mile from the spot where it was 

 first found. Each such spot will contain probably as many as four 

 or six or seven species ; but to that spot all those species are con- 

 fined. In the following descriptions it v>ill be seen that the habitat 

 of six species is certainly " Peace River : " and that of eight species 

 as certainly Yallahs Hill. The latter I have personally explored ; 

 one of my lesidences was near by, and I repeatedly visited it ; and I 

 have no hesitation in saying that none of those eight species are to 

 be found at half a mde either way. There are hundreds of spots 

 of this kind in the island never trodden by human foot, and there- 

 fore there is no knowing how many Stoastotyiidce and other minute 

 shells might yet be found, or how many of other genera, from large 

 to small, may yet be added to the terrestrial conchology of Jamaica. 

 The number of unique specimens in my cabinet tells us this truth, 



