SCALES 



977 



in only termed the ' battledore ' scales, from their resemblance in 

 form to that object (fig. 724, ). These scales, which occur in the 

 males of several genera of the family Lyccenidce, and present a 

 considerable variety of shape, 1 are marked by narrow longitudinal 

 ribbings, which at intervals seem to expand into rounded or oval 

 elevations that give to the scales a dotted appearance (fig. 725) ; at 

 the lower part of the scale, however, these dots are wanting. 

 Dr. Anthony describes and figures them as elevated bodies, some 

 what resembling dumb-bells or shirt-studs, ranged along the ribs, 

 and standing out from the general surface. 2 Other good observers, 

 however, whilst recognising the stud-like bodies described by Dr. 

 Anthony, regard them as not projecting from the external surface 

 of the scale, but as interposed between its two lamella? ; 3 and this 

 view seems to the Author to be more conformable than Dr. Anthony's 

 to general probability. 



The more difficult ' test scales ' are furnished by little wingless 

 insects ranked together by Latreille in the order T/ii/fntti/-n. but 



FIG. 724. Scales of Polyommatus Argus 

 (azure blue) : a, battledore scale ; //, 

 interference striae. 



FK;. 725. Battledore scale of 

 Polyommatus . l/y/.s (azure 

 blue). 



now separated by Sir John Lubbock, 1 on account of important 

 differences in internal structure, into the two groups Collembola and 

 true T1ii/xii;n'r<. Of the former of these the Lepismidce constitute 

 the typical family ; and the scale of the common Lepisnut, saccha- 

 or ' sugar-louse,' 3 very early attracted the attention of 



1 See Watson, Joe. cit. 



- ' The Markings on the Battledore Scales of some of the Lepidoptera ' in Monthly 

 Microm-opicul Journal, vol. vii. 1872, pp. 1, 250. 



~' See ' Proceedings of the Microscopical Society,' op. cit. p. 278. 



4 Bee his MonograpJi of the Collembola and Thysanura, published by the Ray 

 Society, 1*72. 



"' This insect maybe found in most old houses, frequenting damp warm cupboards, 

 and especially such as contain sweets ; it may be readily caught in a small pill-box, 

 which should have a few pinholes in the lid; and if a drop of chloroform be put 

 over the holes the inmate will soon become insensible, and may be then turned out 

 upon a piece of clean paper, and some of its scales transferred to a slip of glass by 

 simply pressing this gently on its body. 



3 R 



