DESCRIPTION OF PLATES. 



The number of diameters which each object is magaified, is expressed in the Plates by small figures 



placed beneath the objects. 



PLATE 1.— Test-Objects. 



Figure 



1. Hairs of the larva of Dermestes lardariuSy viewed in balsam. 



2. Hairs of the common bat {Vespertilio jiipistrellus)^ in balsam, a 6, coloured 



hairs ; c, a white hair. 



3. Hairs of mouse (^Mus domesticus), in balsam. 



4. Pits of coniferous wood, common deal (Abies excelsa), viewed dry. 



5. Mucus- (or salivary) corpuscles, seen under different powers. 



6. Scales of Lepisma saccharina, dry. 



r. Scale from the wing of Morpho meneJauSy dry. 



8. Scale from under side of wing of common clothes-moth {Tinea vestianella), dry. 



9. Scales of Hipparchia janira. a, dry, and by oblique light ; b, in balsam, by 



direct light ; c, dry, after Schacht. 



10. Didymohelix ferruginea, under different powers ; 6, with imperfect correction 



or adjustment, c with perfect correction and adjustment ; c?, separate fibres. 



11. Didymoprium Grevillii, empty cells. 



12. Scales of Podura plumbeay under different powers, dry; a, 220 diameters. 



13. Pygidium of flea. 



14. Frustule of Gra.nmatophora marina (diagram), a, front view ; i, side view. 



15. Frustule of GrammatopTiora subtilissima (diagram). «, front view; 5, side view. 



16. Gyrosigma angulatiim ; dry valve showing the dots. 



17. Gyrosigma attenuatum ; dry valve showing the lines. 



18. Gyrosigma elongatum ; dry valve showing the lines. 



