20 



PSYCHE. 



I March— April iSS^. 



folds, are visible upon thcni. The 

 shank and a little of the basal portion of 

 the scales are hollow ; whether the whole 

 scale is hollow I have not determined. 



Treatment with water, alcohol, glyc- 

 erin or turpentin iloes not seem to affect 

 the scales of Chalcolepidiiis. whicli ap- 

 pear to contain no air. They are not 

 bleached bv chlorin ble;rt;hin<j reasients. 



SCALES OF ALAU.S. 



The two velvety black spots upon the 

 dorsal surface (jf the thorax of yl. ocula- 

 tiis, to which this insect owes its specific 

 name, are formed of scales, as are also 

 all the white portions of the beetle, the 

 •ground color of the whole insect being 

 a slightly shining black. The same re- 

 marks apply to A. my ops, the scales of 

 which are like those of ^. ociilatus in 

 every respect. 



Fig. 7. Scales oi Aiaits oailatuf:: c, brown scale; b 

 anti r, portions of white scales to show cross-bantls; rf, 

 transverse section of a brown scale. Enlargement : .i, 

 100 iliani. ; /» and f, 300 diani. ; li, 500 diani. 



The form of all the scales of A. ocu- 

 latiis is scajjlioid. with the concave side 

 towartl the insect. The scales are stri- 

 ate on the convex side, but smooth on 

 the concave side, Fig. 7, «, illustrates 

 their form, the lower end being the one 

 attached to the insect. In some cases 



the sliaidv b\ which the scale is attaclied 

 is proportionallv longer than is shown 

 in the figure. These scales are inserted 

 by their shanks in holes irregularly dis- 

 tributed in the chitinous covering of the 

 insect. The irregular arrangement, pe- 

 culiar form and stri:ition, and mode of 

 insertion of the scales of A. ocuJatus 

 forcibly remind one of the leaves in a 

 bed of lily-of-thc-valley {ConvaHart'a) 

 when these leaves are blown toward one 

 direction by a gentle breeze. 



The scales of A. ocu/atus are all of 

 tibout the same size — about o.30 to 0.23 

 mm. long by 0.04 to 0.05 mm. wide, and 

 0.005 '"'"• i" greatest thickness — from 

 whatever part of t!ie insect they are 

 taken. Those which form the two 

 black thoracic spots are deep brown 

 when seen under the microscope, and 

 the others are opake white wiien dry. 

 The striae of these scales are about 

 0.0035 'ii'ii- apart, and converge some- 

 what toward each end of the scales. 

 The striae of the white scales are a lit- 

 tle less distinct than are those of the 

 dark scales, the whole white scale, to 

 appearance, when viewed with a low- 

 power microscope, being covered with 

 minute cross-lines, so numerous as to 

 give the scale an opake white color. 

 Under higher magnifying power these 

 transverse lines present an appearance 

 as in fig. 7, b and c. The longitudinal 

 striae are above the transverse lines, i.e., 

 on the convex side of the scales, while 

 the cross-lines extend as interrupted, 

 transverse bands across the lower f)r 

 concave part of the scales. Xo trans- 

 verse bands are visible, even after re- 



