26 



THE HORN-MOUTH, 



conical, quite rough and jagged, and the body whorl 

 is guarded by a crown of strong, sharp points. The 

 operculum, like that of all similar shells, is thin and 

 horny. The color of the shell is a dull white, some- 

 what tinged with brown. 



Fig. 8 introduces us to another southern shell, 

 Cerostoma Nuttallii^ Conr., Se-ros'-to-ma Nutt-alF-i-i, 

 which we may translate as Nuttall's Hornmouth. In 

 the latter part of the book you will find a brief notice 

 of Mr. Nuttall, for whom this species was named by 

 Mr. Conrad, about whom also you will find a few 

 words. If you examine a full-grown 

 shell of this species you will find a 

 sharp tooth, or horn, near the base 

 of the outer lip. The presence of 

 this horn on the rim of the aperture 

 is so peculiar a feature that a name 

 was chosen for the genus which 

 should indicate its presence. We 

 shall find the Greek word for mouth, 

 stoma^ combined in various ways to 

 form the names of different genera, 

 as ChlorostojJia, the Green-mouth, 

 Calliostouia, the Beautiful-mouth, 

 2ca.^ Melanostoma^ the Black-mouth. 



Fig. 8. 



as you 



the 



Our Cerostoma^ 

 has 



or Horn-mouth, 

 a distinct 



see m tne engravmg, nas a aistinct spire 

 marked by ridgelike varices, a small aperture, and a 

 closed canal. 



Some young specimens have no horn on the wall 

 of the aperture, and have an open instead of a closed 

 canal. Allowance must always be made for the age 

 and development of the specimen. Most of the draw- 

 ings in this book were made from adult specimens, 



