GASTEROPODA. 



179 



bular, covered with a white opaque skin, and are about 

 two and a half lines in diameter. Mr. Cuming says that 

 the H. sarcinosa deposits a great number of small eggs on 

 the leaves of the trees in the dark forests of the Philip- 

 pines, and that after the eggs are deposited on the leaf 

 chosen, the animal wraps it round them subconically, so 

 as to resemble in a degree the small paper wrappers in 

 which grocers hand their wares to their customers.* 



Helices are sometimes curiously deformed: Mr. Gray 

 mentions having seen a specimen of H. aspersa which had 

 been curiously thrown out of its proper shape by a young 

 specimen having attached itself to the side, doubtless 

 during the dry season, and not awaking from its torpor 

 so early as its older companion, the latter, when it com- 

 menced increasing the size of its shell, threw its new 

 whorl partly over the smaller individual, which was thus 

 inclosed in a prison formed by its own shell. In this 

 instance the form of the larger specimen was not much 

 altered, but about one-half of the young shell projects 

 above the spire. f In the British Museum there is a speci- 

 men of the H. terrestris with a small stick passing through 

 it, and projecting from the apex and umbilicus. Mr. 

 Pickering has in his collection a specimen of H. hortensis 

 wl)ach got entangled in a nut-shell when young, and 

 growing too large to escape, had to endure the incubus 

 to the end of its days. \ 



This extensive group has been divided by some writers 

 into a great many different genera; for instance, Beck 

 makes forty-five, and Albers sixty-eight, but very few of 

 them have been generally adopted. 



Those who wish to be particularly acquainted with the 



* Pro. Zool. Society, 1840. f Philosophical Trans. 1833. 



% W oodward's Recent and Fossil Shells. 



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