ILLUSTEATIONS IN THE TEXT. XV 



FIGS. PAGE 



148. — Gyphoderia trochus and vars. palustris and 



amphoralis : outlines of tests . 80 

 149,150. — „ trochus vsiiV. amphoralis : portions 



of tests 82 



151. — Trinema enchelys : portions of tests . . 90 



152. — ,, „ scales and apertures . 90 



153. — Trinema lineare : outlines of tests . . 93 

 154. — Pseudodifflugia archeri . . . .121 

 155, 156. — Lieberhuehnia wageneri . . 135, 186 



157, 158. — Allogromia fluvialis . . . 140 



159. — Amphitrema stenostoma .... 152 



160. — Trinema enchelys, after Bhrenberg (1838) . 152 



