198 ZONITES. 



V\5 



? c%o a C H. INTERNA, Say. PL 60, figs. 20-22. 



Very narrowly perforated, brownish corneous, lighter. on the 

 base ; whorls 8, with regular small, close oblique ribs and inter- 

 mediate grooves, and deeply impressed suture, base smooth, 

 polished, umbilical region indented ; within the aperture, upon 

 the exterior portion of the base are two prominent, white lamelli- 

 form teeth, of which the upper one is strongest. Diam. 6 mill. 



Western Pennsylvania to Missouri, South to Georgia. 

 ft o- H. pomum-adami, Green, is a synonym. 



H. SIGNIFICANS, Bland. PL 60, figs. 23, 24. 



V" 4>*^ Narrowly umbilicated, thin, finely irregularly striate above, 

 almost smooth below; whorls 6, narrow, subplanulate, the last 

 roundly inflated, rather flat on the base, and excavated around 

 the umbilicus. Diam. 4'5 mill. 



Union Co., Tennessee ; Fort Gibson, Indian Territory. 



Yiewed through the base there are three pairs of white teeth 



visible, which gradually disappear as the shell grows old ; whilst 



in the nearly allied but smaller H. multidentata the teeth are five 



or six in each radiating row. 



H. MULTIDENTATA, Binney. PL 60, figs. 25, 26. 



Narrowly umbilicated, subplanulate above, very thin, pellucid, 

 smooth, shining; whorls 6, narrow, slowly increasing, delicately 

 striated above, suture impressed, base convex, indented around 

 the umbilicus ; through the base may be seen three or four radi- 

 ating rows of small white teeth, about five or six in each row. 

 Diam. 3-25 mill. 



Canada, Northern portions of the United States, 



Maine to Ohio. 



H. ANDREWSI, W. G. Binuey. PL 60, figs. 27, 28. 

 



Narrowly umbilicated, depressed ; whorls 8^, narrow, the last 



well rounded below ; viewed through the base it has five parallel 

 lamellae. Diam. 6'5 mill. 



Roan ML, N. Carolina. 



" From L. significans it differs in its larger size, greater 

 number of whorls, much wider umbilicus, and in the character 

 of its internal denticles, which are long and winding on the wall 

 of the whorl ; while in significans the denticles are simply erect 

 and conical, with broad base. The same differences distinguish 



