Pierce." Mengury Interruftek. 



Plate 3. 







*\ H^. V 



^ fti(iff»* ^ 





Fie, 8 



/: 



V 



I 



/ 



y- 



; ( 





.^'- 



■■^.>^- ^ 



Fig. 9. 



Pr.oc. Amer. Acad. Arts and Sciences. Vol. XXXIX. 



