242 PROCEEDINGS OF THE ACADEMY OF 



Plate XVII. 



Central, lateral, and outer marginal teeth of: — 

 Fig. 1, Zonites multidentatus, Binn. 

 Fig. 2. Zonites suppressus, Say. 

 Fig. 3. Zonites indentatus, Say. 

 Fig. 4. Zonites arboi'eus, Say. 

 Fig. 5. Zonites fulvus, Drap. 

 Fig. 6. Zonites viridulus, Mke. 

 Fig. 7. Zonites nitidus, Miill. 

 Fig. 8. Zonites milium, Morse. 

 Fig. 9. Zonites ferreus, Morse. 

 Fig. 10. Veronicella Floridana, Binn. 

 Fig. 11. Succinea Sillimani, Bland. 



Plate XVIII. 



a. Central and lateral teeth. 



b. Transition from laterals to marginals. 



c. Inner marginal teeth. 



d. Outer marginal teeth. 

 Fig. 1. Helix Wheatleyi, Bland. 

 Fig. 2. Helix thyroides, Say. 



Fig. 3. Helix Pennsylvanica, Green. 



Fig. 4. Helix loricata, Gld. 



Fig. 5. Helix Mitchelliana, Lea. 



Fig. 6. Helix pulchella, Miill. 



Fig. 7. Helix labyrinthica, Say. 



Fig. 8. Helix Townsendiana, Lea. 



Fig. 9. Helix asteriscus, Morse. 



Fig. 10. Helix obstricta, Say. 



Note. — The following typographical errors in the earlier pages of this 

 paper should be carefully corrected : — 



p. 141, third line from bottom, for Paluta read Patula. 



p. 146, line 11, for former read latter. 



p. 147, line 20, for Aiiaderiis read Aiiadenus. 



p. 148, line 12, for Siinpulopsiis read Slmpiilopsis. 



p. 153, line 17 from bottom of right hand column, for Terussacia read Ferussacia. 



line 16, for CfBoilianella read Ccecilianella ; also on p. 186. 

 p. 154, line 11 of left hand column, for Columbianaus read Columbianus. 

 p. 155, note, ior ptychoptora read ptycop/iora. 



