PLATE XVIII. 



I'HOC. EXT. SOC. WASH., VOL. XVI. 



/ FIG. 5 HYDRpSCAEHA 



h-- 



FIG 6 HYBR, 



'-pap 



FIG,. 7 HfDR 



-1m 



t- 

 1m 



Fia.8 



HYOR. 



1m 



FIG.9 



HYDR. 



FJGs.ll FIG,.] 2 



FJGs.14 OCHT. 



FIG,. 16 



OCHT. 



