73 



On Podur^. By S. J. M'Intire. 

 (Read April 2Uh, 1868.; 



Having lately, through the kindness of a friend, had the quiet 

 perusal of Sir John Lubbock's three papers in the " Transactions 

 of the Linnean Society," on the Thysanura, I beg to offer the fol- 

 lowing corrections and remarks on the notes upon Podurae, which 

 I had the pleasure of reading in November, 1866, and which ap- 

 pear, with illustrations, in " Science Gossip," vol. 3, page 53, &c. 



The first illustration, figure 37, is Isotoma trifasciata, a species 

 often occurring amongst moss in wet places, and at the roots of old 

 trees. It is of a greenish yellow colour, with purplish brown 

 patches, forming three, more or less, continuous bands down the 

 back ; — hence its name. The genus Isotoma has the four anterior 

 abdominal segments sub-equal, and the two posterior segments 

 small. It has hairs, but no scales ; its antennas are four-jointed 

 and longer than the head, the segments being sub-equal, and the 

 eyes are seven in number on each side, and arranged in the form 

 of the letter S. Several species have been noted in England 

 already. 



Figures 38, 39, 40, 42, and 48, all refer to the genus Lepido- 

 cyrtus, probably L. curvicollis. From continued observations on 

 the life history of this genus, I conclude that at different periods 

 the creature wears different aspects. Thus, on escaping from the 

 ^gg, it is plentifully supplied with hairs, which, I think, are 

 clubbed similar to those which Sir John Lubbock says are peculiar 

 to Degeeria and Orchesella only. At the 6rst moult these hairs 

 disappear, and slight iridescence is acquired, which in subse- 

 quent moults is increased, as is also the humped appearance or 

 curvature of the neck, shown in figure 39, representing adult speci- 

 mens. The renewal of the scaly armour is frequent ; and since the 

 skin below the scales is of a yellowish white, a specimen captured 

 shortly previous to the operation is very likely to be taken for a 

 different species. Questions that have been put to me by several 

 members of the club on this point, satisfy me that this is a very 

 frequent mistake. After the change, the colour, to the unassisted 

 eye, is dull leaden black, but under the microscope, gorgeously iri- 

 descent. Large scales, the standard tests of the opticians, are 



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