(im: ) 
the fore wings of the female. In seven specimens there was 
a white spot on this band, and in ten specimens it was absent. 
Mr. Elwes exhibited a large number of specimens of Chryso- 
phanus phleas from various localities in Europe, Asia, and 
North America, with the object of showing that the species is 
scarcely affected by variations of temperature, which was 
contrary to the opinion expressed by Mr. Merrifield in his 
recent paper ‘‘On the effects of temperature in the pupal 
stage on colouring.” 
Mr. Tutt remarked that on the whole the specimens ex. 
hibited by Mr. Elwes tended to prove the point brought 
forward, viz., that the males of (. phigas were, as a rule, 
brighter in more northern latitudes and at greater altitudes, 
whilst those from more southern localities were more suffused ; 
and that no doubt the reasons why a few specimens did not 
exhibit this general tendency could be explained, if the local 
conditions were more perfectly known. 
Mr. McLachlan, Mr. A. J. Chitty, Mr.Bethune-Baker, Mr. 
Barrett, and Mr. Frohawk continued the discussion. 
Papers read, dc. 
Dr. Sharp read a paper entitled ‘‘ On Stridulating Ants.” 
He said that examination revealed the existence in ants of the 
most perfect stridulating or sound-producing organs yet dis- 
covered in insects; they are situated on the 2nd and 8rd 
segments of the abdomen, and the perfection of the articu- 
lations of these segments gives them admirable delicacy of 
movement. These organs exist only in certain ants, and, so 
far as he knew, are not found at all in the Formicides proper. 
In the Ponerides they exist in a stage of development varying 
according to the species, and in the lower conditions of the 
organ they seem to be formed merely of the sculpture of the 
surface, which becomes more perfect and regular. Our little 
English ant, Ponera castanea, possesses a band about the 150th 
part of an inch long, which has about 60 perfectly parallel 
slightly curved lines on it, being at the rate of about 9000 lines 
to the inch. The stridulating apparatus is as a rule more 
perfect in the Myrmicides than it is in the Ponerides, and 
seems to surpass, in the number of lines and their fineness, 
