838 EXPLANATION OF PLATES. 



Fig. 12. Nervous system of Gryllotalpa vulgaris magnified two diameters, 

 seep. 276; 1, first nerve-ganglion with the optic nerves and 

 those of the antennae, behind it a ring, through which the 

 oesophagus passes ; 2 10, the succeeding nerve-ganglia. 



Fig. 13. Head and first piece of thorax (prothorax, corselet) of Gryllotalpa 

 vulgaris seen from above, slightly magnified; A, A, compound 

 eyes; a, a, simple eyes, ocelli or stemmata. See p. 249. 



Fig. 14. A small piece of the cornea of a compound eye from Sphinx 

 atropos, with the hexangular facettes, magnified 200 diameters ; 

 see p. 279. 



Fig. 15. A piece of the under surface of an upper wing from NympJialis 

 urticce, p. 411, magnified more than 40 diameters, and drawn by 

 means of incident light. The surface divested of scales then 

 appears black ; the places for the attachment of the scales are 

 seen as white points. Comp. p. 390. 



Fig. 16. Scales from the upper surface of the upper wing of the same 

 insect, magnified about 75 diameters, and drawn by means of 

 transmitted light under a microscope of OBERHAUSER, p. 390. 



PLATE VIII. INSECTS. 



Fig. 1. Scales of Machilis maritima, p. 297, seen under the microscope. 

 Fig. 2. Lepisma saccharina (p. 298) ; magnified and seen on the under 



surface, after G. R TREVIRANUS Verm. Schr. n. Tab. n. fig. 1. 

 Fig. 3. Trichodectes Equi magnified, as an example of Mallophaga, 



pp. 301, 302, after GURLT Magaz. f. d. gesammt. Thierheilk. ix. 



Tab. i. figs. 4 6. A, from above ; B, from below, attached to a 



hair; c, the jaws; the absolute size is indicated by a line, as is 



also done in figs. 2 and 4. 

 Fig. 4. Pulex penetrans, male, (p. 305). 

 Fig. 5. The pregnant female. Both this figure and the preceding after 



DUMERIL Cons. gen. s. I. Ins. PL 53, figs. 4, 5. 

 Fig. 6. Xenos Peckii, female, (p. 307), after KIRBY Linn. Transact. XL, 



magnified ; a, a, the shield-covers (elytra). 

 Fig. 7. Xenos Rossii, female, magnified, after V. SIEBOLD. 

 Fig. 8. Bombylius discolor, p. 334. 

 Figs. 9, 10. Upper wings of Hymenoptera, fig. 9 of Apis mellijlca, fig. 10 



of Bombus ; pp. 347, 348 ; m, e, outer margin (margo exterior); 



a, apex ; b, base ; m, p, posterior margin ; m, i, internal margin ; 



s, t, stigma; A, radius; c, cubitus ; c, r, cellula radialis ; c,c, c,c, c,c, 



cellulce cubitales; c, d, cellula disco'idalis; c,h, c,h, cellules humer- 



ales; n, b } nervi brachiales. 



