SIR JOHN LUBBOCK ON THYSANURA. | 297 
Lipuridæ and Anuridæ contain at present only a single genus each. The Poduridæ, on 
the contrary, contain nine genera, which may be distinguished from one ARE, as in 
the following table :— 
| Without A A sites Ser D OT Papirius. 
Body globular. . With trachee ...... Antenne 4-jointed o-se cess ss caste san nevis nr scentess ees Smynthurus. 
Antennas BJ ,., o vcs ete ANN eee edo M OPE ET TS AC T a. 
Antennas 6-Jointed sssr ss a ana mie me whe eae ee A Orchesella. 
Terminal sog- - en Eyes 7 in| Choreutes (or 
ment of an age each group Tomocerus). 
ét me tennæ ringed din 
J ‘a Eyes absent.. Tritomurus. 
2 , | With scales Third segment simple ...... Templetoniá. 
; |n und en — [vii No eyes .. .. Beckia. 
Saltatorial - 5-jointed . . tennæ simple "Head ex o iouis Seira. 
. ead moro or] oF Fi concealed 
Que ge iro rl idocyrtus, 
Body elon- "Without scales Abdominal seg- ntu] bo vee bea’ seu à 
- T ments ...... subequal .......... Isotoma 
| Saltatory appendage short... $ Foot with one dm Lee nee fodere 
: Mouth nine. E ARRET eee NE are Lipura. 
Non-saltatorial .... | Mouth > A ares hae : ; Anura. 
EXPLANATION OF THE PLATES. 
PLATE XLV. 
Fig. 1. Outline of a mutilated antenna of Orchesella cincta, April 11, x 60. 
Fig. 2. The same, April 12, x 60. 
Fig. 3. The same, April 19, x 60. 
Fig. 4. The same, May 8, x 60. 
Fig. 5. Outline of another mutilated antenna of the same species, June 5, x 60. 
Fig. 6. The same, June 17, x 60. 
Fig. 7. The same, June 24, x 60. 
Fig. 8. Part of head of Smynthurus, from below, to show the orifice of the tracheæ. 
Fig. 9. Part of respiratory system of Smynthurus, x 30. 
Fig. 10. Smynthurus, side view, with the spring retracted, x 125. 
Fig. 11. Smynthurus, side view, with the spring extended, x 125. 
Fig. 12. Ventral tube, partially extended, with its muscles. x 125. 
Fig. 13. Muscles of stomach of Choreutes, x 125. 
Prare XLVI. 
Fig. 14. Muscles of stomach of Choreutes, x 125. 
Fig. 15. Underside of posterior end of abdomen of Choreutes, x 125. 
Fig. 16. Muscles of stomach of Choreutes, x 125. 
Fig. 17. Portion of skin of Choreutes, x 125. 
Fig. 18. Side view of abdomen of Choreutes, to show the muscles (inner layer), x 125. 
Fig. 19. Side view of abdomen of Choreutes, to show the muscles (outer layer), x 125. 
Fig. 20. Arrangement of muscles on the ventral surface of the posterior abdominal segments of 
Choreutes. 
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