253 



NOTES ON EBORIA CAUGINOSA FALCONER. 



WM. FALCONER, 



Slaithxciiite, HuildersfieUi. 



Previously unsuccessful on more than one occasion in the 

 .autumn of 1909, I again, on March 26th and 31st last, met with 

 both sexes of Eboria caliginosa Falconer, in the same place 

 (elevation 1000 feet) whence came the original types described 

 and figured in ' The Naturalist,' February 1910, pp. 83-88, the 

 two visits after a long and close search yielding one male and 

 six females, all adult. The additional material thus obtained 

 enables me to supplement my description loc. cit. in one or two 

 particulars. It has been suggested to me that possibly the 

 female might not be the proper mate for the male. The two 

 have, however, again occurred in each other's company ; the 

 difference, too, between them is not 

 greater than happens in the case of 

 many others, (indeed it is less than in 

 * Some), so that there can be, I think, 

 little doubt that they are properly allo- 

 cated to each other. 



Stridulating apparatus As I suspected from the structure of 



of r? Eboria caliqinosa r j-t, 1 • • ^ /u ^ • • j. 



Falcr ^'"'^ °^ ^^^ ^^§ jomts, (but, m my anxiety 



to preserve the solitary type specimens in 

 as unmutilated a condition as possible, could not ascertain to 

 my satisfaction), both sexes have a stridulating apparatus which 

 is in duplicate, one set on each side of the body, and each set 

 •consisting of two parts : — 



1. A sounding surface on the outer side of the fore ex- 



tremity of the ventral surface of the abdomen, 

 formed by the spiracular plates which are for this 

 purpose covered with a close series of raised trans- 

 verse chitinous edges (marked a in sketch). 



2. A sound producer formed by the corneous blimt pro- 



jection at the inner side of the fore extremity of 



the coxal of the fourth pair of legs (marked h in 



sketch). 



The latter process is in position to act upon the former, and 



when scraped across it produces a sound inappreciable by 



human ears, but perceptible and serving as a love call to the 



opposite sex during the pairing season. The organ in the male 



is very strong and distinct, but in the female is much weaker 



and less discernible. 



jgio July I. 



