MOLLUSCA OF THE PHILIP?: 



395 



which the nearest allies are found in Australia and the islands 

 of the Pacific are easily recognisable at the first glance by the 

 mantle lobes, which cover the thin transparent shell, and by their 

 remarkably long, narrow, high-ridged tail, which ends abruptly 

 in a gland ; a kind of horn, sometimes of some length, projects 

 from the tip of the tail. The numerous species of which the 

 various distinguishing characteristics are much more conspicuous 

 in anatomical details than in the shell live on trees in damp 

 woods, often in great multitudes ; they are very active and creep 

 about with considerable rapidity upon the twigs and leaves of 



Fre. 105. , RJiysola Anbmii, land mollusc of the Philippines, mimicked by 



mindaittfjitis. which lives associated with it ; c. t/flicario* tiyrinus, mimicked by 

 JCala Cumingii from the same locality, fialinat. size. 



the trees. Every species that I personally examined possessed 

 the singular property, which many lizards have particularly 

 the Geckoes of shedding their tail when they are seized some- 

 what roughly, at a little way behind the shell. This they do by 

 whisking the tail up and down with extraordinary rapidity, 

 almost convulsively, till it drops off; if the creature is held by 

 the tail, it immediately falls to the ground, where it easily hides 

 among the leaves. If it is laid flat on the hand, the rapid 

 wagging movement is strong enough to raise the body with a 



