The Chrysalis Shells and Door Shells 



large enough to catch the eye of the amateur. But it interests 

 the collector, who has his mind on what of beauty and truth the 

 microscope yields. This tiny mollusk hustles along at an awkward 

 but speedy pace for a snail, alternately setting its snout on a 

 spot and drawing the body up to it. Look for it in wet places 

 along stream banks. 



Habitat. — Maine to Texas. 



Genus STROPHIA, Alb. (CERION, Morch.) 



Shell large, oblong, cylindrical, longitudinally ribbed or 

 costate, solid, white; aperture oval; Hp expanded; columella 

 folded. Dentition as in Helix. 



S. incana, Binn., is our only representative of this West 

 Indian genus. It is found on low ground, or under stones, at 

 Key West near tide marshes, and clinging to plants. In winter 

 it secretes an epiphragm of thin membrane. The chalky, solid 

 shell is sometimes streaked with reddish brown. Length, i inch. 



Habitat. — Florida Keys. 



S. decumana, Fer., of the Bahamas, has the form of a silk- 

 worm's cocoon, but is white, and pierced by a tubular umbilicus. 



This is one of the largest species. 



S. chrysalis, Fer., blunt, stout, its flat coils strongly cross- 

 ribbed and spotted, is a Cuban chrysalis shell. Length, i^ inches. 



THE DOOR SHELLS 

 Genus CLAUSILIA, Drap. 



Shell slenderly fusiform, usually sinistral, aperture ear- 

 shaped, guarded by wall ridges, and closed by a shelly plate at- 

 tached to the columella by an elastic foot. It is for the exclusion 

 of small beetles and other insects. A genus of seven hundred 

 species, all terrestrial, with shells mostly turned to the left. 



The Three-Toothed Door Shell, (C. tridens, Chemn.), 

 slim, brown, with a flaring, three-toothed, white lip, has its six 

 whorls longitudinally grooved, and its tip rounded to a blunt 

 point. Length, li inches. 



Habitat. — West Indies. 



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