II HABITS OF CARNIVOROUS SNAILS AND SLUGS 51 



Mexico. Dendronotus arhorescens^ when confined in a glass jar 

 of sea water, has been noticed^ to emit a sound like the clink of 

 a- steel wire. According to Lieut.-Col. Portlock,^ F.\i.^.^ Helix 

 aperta, a very common sj^ecies in South Europe, has the property 

 of emitting sounds when irritated. When at Corfu, he noticed 

 that if the animal is irritated by a touch with a piece of straw 

 or other light material, it emits a noise, as if grumbling at 

 being disturbed. He kept a specimen in his house for a con- 

 siderable time, which would make this noise whenever it was 

 touched. 



The Rev. H. G. Barnacle describes the musical properties of 

 Acliatinella in the following terms : ^ " When up the mountains 

 of Oahu I heard the grandest but wildest music, as from hun- 

 dreds of Aeolian harps, wafted to me on the breezes, and my 

 companion (a native) told me it came from, as he called them, 

 the singing shells. It was sublime. I could not believe it, but 

 a tree close at hand proved it. On it were many of the Aclia- 

 tinella^ the animals drawing after them their shells, which grated 

 against the wood and so caused a sound ; the multitude of 

 sounds produced the fanciful music. On this one tree I took 70 

 shells of all varieties." 



Habits of the Agnatha. — Not much is known of the habits 

 and mode of life of the Agnatha^ or carnivorous Land Mollusca. 

 In this country we have only two, or at most three, of this 

 group, belonging to the genus Testacella, and, in all probability, 

 not indigenous to our shores. There seems little doubt, when 

 all the circumstances of their discovery are taken into account, 

 that both Testacella haliotidea and T. Maugei have been im- 

 ported, perhaps from Spain or Portugal in the first instance, 

 along with roots imbedded in foreign earth, for their earliest 

 appearances can almost invariably be traced back to the neigh- 

 bourhood of large nursery grounds, or else to gardens supplied 

 directly from such establishments. 



The underground life of Testacella makes observation of its 

 habits difificult. It is believed to feed exclusively on earth- 

 worms, which it pursues in their burrows. Continued wet 

 weather drives it to the surface, for though loving damp soil it 



1 Dr. R. E. Grant, Edinh. Phil. Jonrn. xiv. p. 188. 



2 Bep. Brit. Ass. for 1848, p. 80. The statement is confirmed by Rossmassler. 

 ^ Journ. of Conch, iv. p. 118. 



