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-all'-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 Chlorostoma, the Green-mouth, 

 Callwsto?na, the Beautiful-mouth, 

 and Melanostoma, the Black-mouth. 

 Our Cerostoma, or Horn-mouth, 

 the engraving, has a distinct 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, 



Fig. S. 



as you see in 



