144 BRITISH CICADA. 



Typhlocyba hippocastani, Edu\ 

 Ent. Mo. Mag. vol. xxv. p. 157, figs, a, h, c. 



For details see Plate XXIV., fig. 8, of this Mouo- 

 grapli. 



Male. Whitish hyaline. Corinm tinged with yellow. 

 Eyes grey. Tips of the tarsi black. Penis with several 

 branched appendages. 



I have examined five specimens of this insect, which 

 were named by Mr. Edwards. They show no external 

 differences, under the microscope, from T. rosce that 

 I could emphasize by drawing and colour. Some of 

 the specimens are pale yellow, whilst others are 

 more ochreous in tint. These examples show no 

 markings of any kind either on body or elytra. 



The paucity of males, contrasted with the number 

 of females, increases the difficulty of identification of 

 specimens, since the latter sex is stated to be of no 

 practical value in diagnosis. 



First taken by Mr. Douglas in October on the under 

 sides of the leaves of the horse-chestnut (^Escidus hippo- 

 castanwn), at Beaufort Gardens, Lewisham. 



Mr. Edwards dissected six males, and he could find 

 in them no individual variation in the structure of the 

 appendages of the penis. As to the import of these 

 organs, he considers that their " undoubted constancy" 

 is of the "utmost value" as a differential character. 



Examples of T. hippocastani have been lent to me by 

 Mr. J. W. Douglas ; but T. opaca and T. pruni have not 

 come under my observation. 



Typhlocyba opaca, Edw. 

 Ent. Mo. Mag. vol. xxv. p. 158, figs, g, h, i. 



Externally in form and colour like the last, but " it 

 maybe distinguished by its dull appearance and opaque 



