164 



R. W. CROSSKEY 



211 



212 



213 



214 



215 



216 



Figs. 211-216. Pupal gill form in subgenus Metomphalus. 211-213, medusaeforme-group. 

 214, albivirgulatum-gi oup. 215 and 216, bovis-gxoup. 



