CLASS II. 
GASTEKOPODA: 
OEDER 2. BRANCHIFEEA. 
SOT 
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 namerous 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 H. alholahris ; 
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 LIMACID^. 
Genus LIMAX : Limax. — This includes several species, called Sluffs ; 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- 
^™ c.„^ 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 lAWSMIDM. 
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, transpare t masses, 
on aquatic plants and stones. There are several minute species in this country. 
I ORDER 2. BRANCHIFERA. 
This order derives its name from the Latin branchice, gills, and fero, to bear, and is divided 
into two groups or sub-orders, the Prosohranchiata, and the Opisthohranchiata. 
THE PKOSOBEANCHIATA. 
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^ID^, 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 Avater 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 Cowry, 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, 
