Tond-snails 



321 



have ca short round foot, a sliort head, and tlie 

 tentacles instead of being flat and triangular, as in 

 Limncp/i, are long and slender, witli the eyes at their 

 inner bases. They are vegetable feeders. 



The Rani's-horn (P. corneus), whicli is tlie largest 

 known species, has the whorl rounded, the mouth an 

 oblique crescent, almost circular. Its colour is reddish 

 brown approaching to white on the upper surface. 

 It measures about 1 inch across, and the breadth of 

 the body-whorl is about one-third. The animal is 

 dark red-brown, approaching black above and paling 

 to grey below. It appears to be absurdly small in 

 proportion to the size of its house, but this enables 

 it to retreat far in when danger threatens, and also 

 when active to carry a large supply 

 of air. When irritated it discharges 

 from a gland in the neck a quantity 

 of red fluid, evidently with the object 



... Rams-horn 



or makmg the vicinity unpleasant. 

 It is not so prolific as some of the smaller species, 

 and only produces from 60 to 120 eggs during the 

 season. These are laid in shield-shaped masses of 

 firm jelly, each containing from 20 to 40 eggs, which 

 hatch in fifteen or sixteen days. The epidermis of 

 young individuals is distinctly downy. Though 

 occurring in many of the English counties, it is a 

 very local species ; in Ireland it has been recorded 

 from Limerick. 



The Twisted Trumpet-snail (P. contortus) contrasts 

 strongly with the Ram's-horn, for tliough it agrees 

 with it in having the whorls rounded, it differs so in 

 size that its greatest diameter is only one-fifth of an 

 inch. In spite of tliis diminutive size it has no less 



