Skills of Common Occurrence. 151 



repose it inclines it at an angle of 70 . It derives 

 its generic name from a shelly bone attached ta 



H 



57 58-59. 



57. Zaa Inbrica (the Common Yarnishcd Shell), IlilUcr. 

 58-59. Azcca tridens (the Glossy Trident Shell), Fulteney. 



the colnmellar teeth^ and termed the claushim, from 

 closing np the aperture when the animal has 

 retired within its habitation. The next little gronp, 

 Zua lubrica (common varnished shell)^ and As'ca 

 tridens (glossy trident shell)^ are parallel in character, 

 only the Zua is toothless, the Azeca ovate and 

 toothed in the mouth. Both inhabit close shady 

 wood, moss_, and under stones and decayed leaves. 

 The one is not quite, the other about, a quarter of 

 an inch in length. The next group comprises the 

 needle agate shell {Acliatina acicula), the shell of 

 the common amber snail {Succinea futris), and two 

 PJnjsce or bubble shells (P. fontinalis and P. hyp' 

 noruin) . The first is indeed minute, interesting, and 

 extremely delicate, having six convolutions, though 

 only a fifth of an inch in length ; but, indeed, dead 

 specimens found in old Saxon coffins are more 

 frequent than living ones occurring amongst roots 

 of grass and moss. Succinea is from succinum, 



