INSECTA. 297 
The nervous system in Smynthwrus presents only four ganglia, of 
which the first and second lie very close together, the first above, 
the second below the cesophagus (Nicouer) ; in Lepisma saccharina, 
on the other hand, Treviranus found twelve ganglia. The two 
eyes, which in most species are small, consist of a group of eight, 
sometimes six or seven, in Podura jimetaria of fourteen simple 
eyes (Nicoter); in Lepisma saccharina twelve simple eyes are 
counted on each side. 
These Insects, however nearly allied to the myriapods, approach 
still more nearly to the Orthoptera, and especially to the genus of the 
earwigs (Yorficule) ; see this Manual, first edition, 1. 1828. pp. 204, 
205. But if, on account of this affinity, any one would place Lepisma, 
or even the whole order of Zhysanura, amongst the Orthoptera, I 
think he would go too far. Time, the touchstone of all things, 
would reject the union. If LarreiLuE had united the Thysanura 
with the Orthoptera in one order, zoologists of the present day 
would for certain have perceived long ago that these Insects were 
not in their place. 
Comp. on this order: TREvIRANUS Verm. Schr. 11. s. 11—17. Tab. I. 
Ill. and Ivy. figs. 1—5 (on the anatomy of the genus Lepisma) ; BURMEISTER 
in OKEN’s Isis, 1834, 8. 137, 138 (on the respiratory organs and the 
stigmata of Lepisma, whose presence TREVIRANUS had erroneously denied) ; 
LatTREILLE, De I’ Organisation extérieure et comparée des Insectes de Vordre 
des Thysanoures, Nouv. Ann. du Mus. 1. 1832, pp. 161—187 ; R. TEMPLE- 
ton, Thysanura Hibernice, or Descriptions of such species of spring-tailed 
Insects, Podura and Lepisma, as have been observed in Ireland, Transact. 
of the Entomol. Soc. London, 1836, 1. pp. 89—98, Pl. x1. x1r.); H. Niconrr 
Recherches pour servir a UV Hist. des Podurelles, 88 pages et g planches 
(Neue Denkschr. der allg. Schweizerische Gesellschaft fiir die gesammt. Natur- 
wissensch. Bd. vi. Neuchatel, 1841, 4t0); Burmuister, Handb. der Enta- 
mologié, II. 2, 1838, s. 443458 ; GERVAIS in WALKENAER, Hist. des Ins. 
aptéres (Suites 1 BUFFON chez RORET), 111. 1824, pp. 377—456, &e. 
Family U1. Lepismene. Body elongate, mostly covered with 
minute scales. Antenne setaceous, with joints numerous, very 
short. Palps four, elongate. Abdomen of nine or ten distinct 
segments, besides other appendages supplied with three (or more 
rarely with two) long setee, articulated towards the extremity. 
Machilis Latr. Antenne inserted under large, contiguous 
(compound ?) eyes. Maxillary palps, exsert, filiform, long. Body 
arcuate, with convex back, saltatory. Three sete at the extremity 
of the abdomen, the middlemost larger than the lateral. 
