EXPLANATION" 'OF PLATES. . ix 



muscles moving the jirothorax ; 1, lima on metathorax ; s, clasp ; spr, prothoracio 

 spiracle, b, Astynotnus cedilis, the Woodman Beetle ; t, prothorax ; /, lima. 



Fig. 3. Metathoracic spiracle of Musca voniitoria, the Blue-bottle Flv. 

 I, Laminae on the operculas of the spiracle ; /;, haltera (internal aspect). 



Fig. 4. A, Metathoracic spiracle of Mclolontha vulgaris, the common Cock- 

 chafer ; I, undulated lips or operculae. b, Metathoracic spiracle of the Humble 

 Bees (Bembus), internal structure; s, external opening of the spiracle; b, cup- 

 shaped cavity ; a, movable internal opercula. (After Landois.) 



Fig. 5. A, Fan of the male Cidaria prunata ; b, fan of the male Cidaria 

 populata. In these moths, belonging to the Geometrina, the fans are inserted at 

 the base of the fore wings. 



Fig. 6. Internal view of the integument of Heliophilus pendulus, a Ilover- 

 fly. I, Laminpe at the opening of the mesothoracic spiracle. These are again 

 shown beneath, as seen ixnder a somewhat greater magnifying power. 



Fig. 7. A, Fan of the male Death's-head Moth, Acherontia Atropos, expanded; 

 B, the same lying in its fold. 



Fig. 8. Exterior anatomy of Mamcstra Brassic(e, the Cabbage Moth. 1, The 

 head; 2 to 4, the segments of the thorax; 5 to- 13, those of the abdomen; 

 a, entrance or adit of the auditory organ : e, that of the Eustachian tube ; 

 X, fan of the male, showing the portion stained by the secretion these organs 

 diffuse darker, as likewise their point of insertion. 



Fig. 9. Fan of the male Catacala Nupta, or common Red Underwing Moth, 

 inserted at the upper extremity of the tibia, a, Fan expanded ; b, the groove 

 into which it shuts. 



PLATE VI. 



ORGANS OF AUDITION IN ORTHOPTERA AND OF STRIDULATION IN COLEOPTERA 

 AND HYMENOPTERA, DRUM OF THE CICADID.'E, ORGAN OF SMELL IN BEES 

 AND GNATS, ORGANS OF CIRCULATION. (VARIOUSLY MAGNIFIED.) 



Fig. 1. The right ear of the grasshojiper, Stetheophymn yrossum, from without. 

 a, The opening in the horny ring ; b, b', composite horny piece seen through the 

 membrane of the drum ; c, the triangular horny piece seen thjrough the mem- 

 brane of the drum. (From a paper by Von Siebold.) 



Fig. 2. The Miillerian ganglion of Truxalis nasuta, L., from China. Iso- 

 lated and prepared with potash, and tinted with carmine. (From a paper by 

 Herr Vitis Graber.) ■ m, Rod-shaped corpuscles ; I, hexagonal cells. 



Fig. 3. Part of the antennae of a Hive Bee, Apis mellijica, and of a Gnat, 

 Ctenophora bimaculata, showing the nerve, «, ramifying to the j^ores, p. (From 

 Dr. Hick's paper in the " Transactions of the Linnfean Society.") 



Fig. 4. Drum of a male cicada, s, Metathoracic spiracle ; p, point of inser- 

 tion of motor tendon. 



Fig. 5. Mirror of a male cicada from within, n, Supposed acoustic nerve. 



Fig. 6. Undeveloped organ of stridulation in a female Leaf-cricket, Decticus 

 vemicivoriis. 



Fig. 7. Organ of stridulation in the Ant, Myrmica riiginoides. p, Pedicle ; 

 a, abdomen ; /, striae. 



Fig. 8. Organ of stridulation in a Solitary Ant, Mutilla. p, Pedicle ; a, 

 second joint of abdomen ; I, lima or file. 



Fig. 9. Interior view of the structure at the base of the abdomen in the 



