CLASS II. GASTEROPODA: ORDER 2. BRANCHIFERA. 507 



are so abundant in Europe, as to have given rise to the popular idea that it has rained snails. 

 In some intertropical countries there are species with exceedingly beautiful shells. 



Snails are less numerous in this country than in Europe, though we have in the United States 

 over sixty known species. One of the largest and most common among us is the JI. alholabris ; 

 this deposits its eggs in light mould by the side of rocks and logs ; in twenty or thirty days the 

 young snail issues forth with a shell containing one whorl and a half. In October this species 

 cease to feed, close the aperture by secreting over it a thin membrane, place the operculum 

 uppermost, and remain torpid till spring. Other American species are the H. alternata, abound- 

 ing in ditches and moist places ; H. monodon, usually living in pairs, and found in open fields 

 under stones, or in rotten wood in forests, &c., &c. 



THE LIMACIDiE. 



Genus LIMx\X : Limax. — This includes several species, called Slugs ; these resemble snails in 



the form of the body, in the number and structure 

 of the tentacles, and in their habits; but their 

 shell is very small or rudimentary, and usually 

 concealed in the interior of the mantle. Many 

 of these species are very destructive in the gar- 

 dens and fields, and a multitude of devices have 



THE BED SLUG. ' 



been adopted for their destruction. The Red 



Slug, L. rufus, is a very abundant species, and in Europe a broth made of it is used for diseases 



of the chest. The Black Slug, L. nigrescens, and Gray Slug, L. griseus, are also common 



European species. The L. agrestis is an American species one and a half inches long, feeding 



on succulent leaves, and is often found on the under side of decayed leaves and trunks lying on 



the ground. Other species are L.flavus, two to two and a half inches long, and L. campestris, 



an inch long, &c. 



THE LIMN^IDJ^. 



These, which are called Pond Snails, inhabit fresh waters in all parts of the world : they feed 

 chiefly on decaying leaves, and deposit their spawn, in the form of oblong, transparent masses, 

 on aquatic plants and stones. There are several minute species in this country. 



ORDER 2. BRANCHIFERA. 



This order derives its name from the Latin bmnchice, gills, and fero, to bear, and is divided 

 into two groups or sub-orders, the Prosobra^ichiata, and the Oinsthobranchiata. 



THE PEOSOBEANCHIATA. 



This term is compounded of the Greek proso, anterior, and branchice, gills, and includes a great 

 number of species, all, however, possessing shells, usually spiral, within which they can retract 

 themselves at pleasure. On account of the anterior position of the gills, the blood flows back 

 toward the breast, and the auricle of the latter organ is placed in front of the ventricle. This 

 division includes a great number of families, some of which we shall very briefly notice. 



THE CYPR^EID^, OR COWRIES. 



In this family the shells are convolute, highly enameled, and many of them are beautifully colored. 

 The animal has a broad foot, truncated in front, and a mantle expanded on each side. There are 

 one hundred and fifty living species ; they are found in all warm seas, except on the east coast of 

 South America ; they generally live in shallow water near the shore, and feed on zoophytes. 



Genus CYPR^A : Cgprcea, includes the C. annulus,used by the Asiatic Islanders to weight 

 their fishing-nets and for barter. Mr. Layard found species of it in the ruins of Nimroud. 



The Money Cow^ry, C. moneta, is a native of the Pacific and Eastern seas, and is used as 

 money by the natives on the coast of Western Africa. These are collected in immense 

 quantities by the British and taken to Africa to be disposed of to the negroes. In 1849, 



