MOLLUSCS 



Gasteropctra Meckeli. 



Bulla Ampulla. 



Bursatella Leacliii. 



In the Gasteroptera Meckeli the body is divided into two parts, the posterior being round and connected 

 by a peduncle with the anterior portion, which is small, but enlarged on each side into a considerable 

 muscular expansion, transversely oval, and hollowed out in the middle, both above and below, rendering 

 this expansion fVn Jblt.-u.oed, and an organ for swimming, instead of a foot for creeping. The side-gill is 

 uncovered an« there is no shell. It abounds in the Sicilian seas. 



in the Bursatella Leachii, the body is nearly round ; below is an oval space surrounded by thick lips, 

 indicating the foot ; above is an oval opening with thick lips, formed by the union of the swimming 

 appendants of the mantle, and communicating with a cavity, in which are formed one very large gill and 

 the vent. The tentacula, or arms, are four, divided and branched, besides two buccal appendages. It is 

 large-sized, and a native of the East Indian seas. 



The Common Snail is of the class Gasteropoda. It is so well known as to need no description. It lays 

 eggs large in comparison with the parent. They are deposited about two inches below the surface of the 

 earth. The Snail is very tenacious of life. 



The Slugs are invaders of the garden like the Snails. They seldom venture out by day, but trail skng 

 through the garden at night, devouring the tender leaves. 



Bulinus is the name of a very large genus of land mollusca, endowed with lungs. These are described, 

 as plant eaters, as respiring by lungs, and as protected by a spiral shell, more or less elongated, oval, oblong, 

 with an aperture longer, than it is wideband with a very irregular border, which in the adult, is retorted. 

 The head is furnished with four tentacula, or horns, the two largest of which are terminated by the so" called 

 eyes. They abound most in the warmer climates, where some of the species are very large. 



The reproduction is by eggs, which are white and have a firm shell like those of birds. The Bulini are 

 genuine hermaphrodites, both the sexual organs being distinct, but existing in the same individual, and 

 recjuiriug the union of two for continuing the species. 



Bulla Velum. 



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