BULLETIN 39, UNITED STATES NATIONAL MUSEUM. [6] 



lofty tree tops of tropical forests still others live j)ermanently, never 

 visiting the ground, and, in their airy domicile, exhibit colors almost 

 as varied and brilliant as the arboreal flowers which surround them- 

 In arid regions some seek the shade of stones or attach themselves to 

 the stems of cacti or other desert plants, while others again adhere to 

 the sunburnt surfaces of rocks so hot as to be uncomfortable to the 

 touch, on which their white or rusty shells stand out conspicuously. It 

 has been generally noted that the color of the shell bears a certain rela- 

 tion to its favorite station, the arboreal forms presenting the brightest 

 and most varied colors ; the moss lovers and terrestrial species being 

 usually dull, horny, or greenish, though often with a brilliant, polished, 

 or delicately sculptured surface; while subterranean forms are usually 

 pale or pellucid. The slugs are usually nocturnal in their habits, 

 retreating to holes and crevices at dawn; the cultivator, whose succu- 

 lent vegetables they destroy, seeing his harvest ravaged without a vis- 

 ible enemy. On one of the Florida keys, built of the debris of coral, 

 and as full of holes and crevices as a sponge, a settler raising early 

 tomatoes for the New York market found to his dismay as the fruit 

 began to ripen that every red one was immediately eviscerated, leaving 

 nothing but the skin. There were no birds, worms, or mice to do such 

 damage, which was not occasional but general over his whole farm. 

 Finding nothing by day he took to scrutiny by night and was rewarded 

 by the discovery of myriads of slugs which proceeded from the inter- 

 stices of the coral and devoured every ripe- fruit. The plague admitted 

 £)f no remedy, the enemy was too numerous, and the unfortunate culti- 

 vator was obliged to abandon his undertaking and go into bankruptcy, 

 Tuined by Veronicella. 



In general, limestone regions are most favorable for land shells and 

 those of flinty rock least advantageous. Woods of coniferous or resin- 

 ous trees are unsuited to their tastes, while those of deciduous soft 

 wooded nature offer a congenial home for the moUusks. Certain pun- 

 gent herbs, especially cruciferoe, are said to be obnoxious to slugs. 

 Gardeners in Europe are said to protect their lettuce beds by a hedge 

 of mustard or pepper grass. Nettles, on the other hand, are a favorite 

 haunt of certain small land shells. Dry coal ashes, alkaline wood ashes 

 wet or dry, sand and lime in a pure state, are more or less effectual in 

 repelling the slugs, which they irritate mechanically. It is probable as 

 far as the smaller species are concerned that the unfavorable nature of 

 resinous trees is due more to the fact that they decay less easily and 

 afford a less favorable nidus for fungi upon which the snails feed than 

 to any direct influence of the resin upon the mollusks. Salt is inimical 

 to most of the Helicidw, but the AuricuUdoe or many of them, Trun- 

 catella and Polygyra, seem to prefer the vicinity of the sea. 



Spring is the most active season for snails as for most animals, they 

 attain their fullest development toward midsummer, and as winter ap- 

 proaches they i3euetrate the ground or in warm regions attach them- 



