8 



RANDOM NOTES ON NATURAL HISTORY. 



end, into the body portion of the shell, and 

 having no fnrther use for the apex, and not 

 being strengthened and protected by the 

 presence of the animal within, it falls off'. 

 In some situations, carbonic acid in the 

 water dissolves off" the thin point, and in 

 others it is eaten off by other carnivorous 

 mollusca ; in these cases the shells are said 

 to be eroded. The shells of these Gaster- 

 opods are built in a spiral form, and coiled 

 around an axis, which is in the centre of 

 the shell, running from the apex to the op- 

 posite end, called the base. Each turn of 

 the shell around its apex constitutes a irhorl ; 

 each whorl as it recedes from the apex be- 

 ing larger in circumference than the pre- 

 ceding one. The line, or groove, formed b}' 

 the junction of the whorls, is called a suture. 

 At the end of the last turn, or body whorl, 

 as it is termed, is the aperture or mouth 

 of the shell. This aperture, in some 

 species, is wholl}^ are partially closed 

 (when the animal has retired into the shell) 

 b}' a horny substance (unlike the material 

 composing the shell) which is attached to 

 the foot of the animal and drawn in after 

 it, forming a sort of door ; this is called an 

 operculum. From the top of the aperture 

 to the apex, embracing all the whorls, is 

 called the sj>ire. The aperture in some 

 families is entire ; in others it is notched 

 or produced into a canal. The margin of 

 the aperture is the peristome; sometimes it 

 is continuous ; frequently it is interrupted ; 

 the left side of the aperture being formed 

 by the body whorl. The right side of the 

 aperture is called the labrum or outer lip ; 

 the left side, the labium or inner lip, also 

 called the columella. 



The base of a shell, at the axis, around 

 which the whorls are coiled is sometimes 

 open or hollow ; this opening is called the 

 umbilicus; and such shells are said to be 

 ■umbilicated, or perforated. In other shells 

 the umbilicus may be filled up by a cal- 

 careous deposit, or covered by the inner lip 

 being expanded over it ; such shells are 

 imperforate. Lines of sculpture, or of color, 

 running from the apex to the aperture are 

 either spArcd or longitudinal ; other lines 

 crossing the whorls are transverse lines, 

 like the lines of growth. Most shells, while 

 the animals inhabit them, are covered with 

 an epidermis, more or less thick, composed 

 of animal matter, similar to the cuticle, or 

 scarf skin upon our bodies, to protect the 



shell from the action of acids, gases, etc., 

 in the air or water in which they live. After 

 the animal dies, and the shell is exposed ta 

 the sun and rain, the epidermis jjeels off", 

 leaving the shell bleached in appearance 

 and not desirable for cabinet specimens. 



The Class Gasteropoda are separated for 

 convenience into three great sub-classes : 

 Prosobranchiata, Opisthobranchiata, and 

 Pulmonifera, the characteristics of which 

 will be described in their proper places. 



{To he continued.) 



CATLINITE. 



The beautiful red stone pipes in collec- 

 tions of Indian culture-objects are made of 

 a stone called catlinite. Mr. E. A. Barber 

 tells us that for man^^ generations the 

 aborigines have procured this material 

 from the great red pipe-stone quarry, situ- 

 ated on the dividing ridge between the 

 Minnesota and Missouri rivers, at a place 

 called by the French, Couteau des Prairies. 

 Catlin, the celebrated traveler, was the 

 first white man permitted by the Indians 

 to visit the place, and therefore Dr. C. T. 

 Jackson, to whom specimens were sent, 

 named the mineral catlinite. The myths 

 relating to the quarry, as well as surface 

 indications, show that the place has been 

 worked for a very long time. 



In 1673 Marquette smoked in peace a 

 catlinite pipe with the Indians of the upper 

 Mississippi. Father Hennepin applies the 

 term " calumet " to these ceremonial pipes. 



There is no doubt that an extensive traf- 

 fic was carried on in this material for a con- 

 siderable length of time by the aborigi- 

 nal tribes, extending from the Atlantic 

 coast to the Rocky Mountain system, and 

 from New York and Minnesota on the 

 north to the Gulf of Mexico. The fact 

 that objects of catlinite have been taken 

 from Indian graves in the State of New 

 York ; and that others were found on the 

 ancient site of an abandoned village in 

 Georgia, at opposite points twelve hundred 

 miles distant from the pipe-stone quarry of 

 Minnesota, reveals the great extent of in- 

 tercommunication which formerl}' existed 

 among the North American peoples. — Am- 

 erican Naturalist, July. — J. W. P. 



