PLATE XX. 



PAGE 



Figs. 1, la, 2. Tor.>-ATELLAEA BELLA Conracl 123 



1. Aqnia Creek. U. S. Xational Museum. 

 la. Dorsal view of same specimen. 



2. Aquia Creek. Acad. Xat. Sci. Phila. Lea Memorial Coll. 



Fig. 3, 3a. EiA-GicuLA dalli Clark 124 



3. Dorsal view. (After Clark.) Woodstock. 



3a. Ventral view of same specimen. (After Aldrich.) 



Figs. 4, 4a. Cylichxa VExrsTA Clark 124 



4. Ventral view of type specimen. Woodstock. 

 4a. Dorsal vie^v of same specimen. 



Figs. 5, 5a. 6. PLEXTROTOiiA HABRlsi Clark 125 



5. 5a. Original figures of type specimen. Potomac Creek. 



6. Specimen ^th more distinct sculpture. Same locality. 



Figs. 7, 7a. PLEmoTOirA poto:uacexsis n. sp 126 



7. Ventral vie^v of type specimen. 2 miles below Potomac Creek. 

 7a. Dorsal rie^v of type specimen. 



Fig. 8. Plel-rotoma DrcATELi n. sp 126 



Dorsal view of type specimen. 1 mile soiitheast of Mason Springs. 



Fig. 9. PLErEOTOirA tysoxi n. sp 126 



Ventral view of type specimen. 1 mile southeast of Mason Springs. 



Figs. 10. 11. Pletjrotoma childreke Lea 127 



10. Ventral A-iew of broken specimen. 1 mile southeast of Mason 



Springs. 



11. Dorsal view of more nearly perfect individual. 



Fig. 12. PLErKOTOMA piscatatt:xsis n. sp 127 



Dorsal vie^v of type specimen. 1 mile northeast of Piscata^vay. 



Figs. 13, 13a. ;NL\xgilia (PLErROTOMELLA) BELLiSTRL\TA Clark 128 



13. Ventral view of type specimen, enlarged as indicated. Popes Creek. 

 13a. Dorsal view of same specimen, natural size. 



