INSECTA. 297 



The nervous system in Smynthurus presents only four ganglia, of 

 which the first and second lie very close together, the first above, 

 the second below the oesophagus (NIC'OLET) ; 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 jvmetaria of fourteen simple 

 eyes (NICOLET) ; 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 (Forficulce) ; see this Manual, first edition, I. 1828. pp. 204, 

 205. But if, on account of this affinity, any one would place Lepisma, 

 or even the whole order of Thysanuro,, amongst the Orthoptera, I 

 think he would go too far. Time, the touchstone of all things, 

 would reject the union. If LATREILLE 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. n. s. n 17. Tab. u. 

 III. and IV. figs, i 5 (on the anatomy of the genus Lepisma) ; BURMEISTEB 

 in OKEN'S Isis, 1834, s. 137, 138 (on the respiratory organs and the 

 stigmata of Lepisma, whose presence TREVIRANUS had erroneously denied) ; 

 LATREILLE, De V Organisation exterieure et comparee des Insectes de I'ordre 

 des Thysanoures, Nouv. Ann. du Mus. i. 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, i. pp. 8998, PI. xi. XIL); H. NICOLET 

 Recherches pour servir a I'Hist. des Podurelles, 88 pages et 9 planches 

 (NeueDenkschr. der allg. Schweizerische Gesellschaft fur die gesammt. Natur- 

 wissensch. Bd. vi. Neuchatel, 1841, 4to) ; BURMEISTER, Handb. der Ento- 

 mologie, n. i, 1838, s. 443 458 ; GERVAIS in WALKENAER, Hist, des Ins. 

 apteres (Suites a BUFFON chez KORET), in. 1824, pp. 377 456, &c. 



Family III. Lepismence. Body elongate, mostly covered with 

 minute scales. Antennas 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 setae, articulated towards the extremity. 



Machilis LATR. Antennae inserted under large, contiguous 

 (compound ?) eyes. Maxillary palps, exsert, filiform, long. Body 

 ircuate, with convex back, saltatory. Three setae at the extremity 

 of the abdomen, the middlemost larger than the lateral. 



