PLATE XIX. 
Fig. 1. Tick of hedgehog, magnified 12 diameters by Tolles’s 
two-inch objective ; in balsam ; heliostat. 
Fie. 2. — Parasite of beetle, magnified 12 diameters; Tolles’s 
two-inch objective ; in balsam ;_heliostat. 
Fia. 8, — Acarus of housefly, magnified 100 diameters ; Col- 
lins’s one-inch objective ; heliostat. 
Fic. 4. — ParasiTE of bat, magnified 50 diameters by Tolles’s 
two-inch objective ; in balsam ; heliostat. 
