*!j°o"umL,"nTmf '] Roijal Microscopical Society. 3 



London Docks in a case of furniture last year, and were kindly- 

 given me by E. T. Loy, Esq., [a very pretty insect of speckled 

 appearance, black, brov?n, and white ;] and another of silvery-white 

 lustre from the West Coast of Africa, for which I am indebted to 

 the same kind friend — a strong family likeness is perceptible, and the 

 resemblance to the scales of the Lepidoptera is very striking.* (See 

 Figs. 1 and 2.) 



Passing on to the scale of Petrobius Maritimus, an insect 

 common on the limestone rocks all round our coasts, remarkable 

 for its activity, whether running or leaping, and known as the 

 Bristle-tail, there is a variation to be noticed, in the fact that the 

 corrugations in many of the scales radiate from a line up the centre, 

 and these corrugations are crossed again by striae at right angles to 

 them. An apparently beaded structure is often seen, but I beheve 

 it is illusive, and the explanation of the whole of the appearances is 

 clear to my mind as the result of corrugations (see Fig, 3). So 

 much for the Lejpismidse. 



Then, in the second division of the Thysanura, the Poduridw, 

 the first example I shall allude to is Macrotoma. As this scale is 

 already sufficiently well depicted for the purpose in this Jonrnal, 

 vol. i., page 208, Fig. 5 J, I need only call attention to it to show the 

 striking similarity between it, the known scales of Lepismidas, and 

 Lepidopterous scales. There are strong ribs or cost^ in a longitu- 

 dinal direction crossed at right angles by minute wrinklings of the 

 membrane, which under very high powers and certain illumination 

 present the appearance (an illusive one, I beheve) of rows of beads, 

 as in the scale of Petrobius just alluded to. Some species of Macro- 

 tomse show this feature better than others ; Macrotoma major for 

 instance. 



In the scale of the greenhouse l>egeeria\ the corrugations are 

 much coarser, fewer in number, slightly curved in direction, and 

 interrupted in their course (more correctly speaking, perhaps, sup- 

 pressed), so that they to a certain extent overlap each other. Of 

 these short costae the ends farthest from the tiny shaft of the scale 

 are considerably the highest. In fact, I take these costae to be the 

 representatives of the " note of exclamation " markings in Jj&pido- 

 cyrtus. (See Fig. 4.) 



In Templetonia NitidaX the structure is the same with these 

 modifications ; — the ridges are closer, and the suppressions or inter- 

 ruptions are more numerous. The sudden terminations of these 

 little costae moreover are perceptibly broader and higher in pro- 

 portion to the length of the costae than in the scale I have just 



* These two scales are almost identical. Those from the speckled insect are a 

 little more opaque than from the silvery-white one, but the shape of the scales and 

 the other features are much tlie same. 



t 'M. M. J..' vol i., p. 203, Fig. 3 h. % Ibid., Fig. 4 h. 



B 2 



