Vol. XXVli] ENTOMOLOGICAL NEWS. 



from minute to relatively large in different species, reaching 

 from about one-sixth the distance to the cereal apex to nearly 

 the apex of those appendages. 



FEMALE GENITAL CHARACTERS. 



The degree of production and median emargination of the 

 supra-anal plate is not a feature of diagnostic value, while the 

 cerci, which Shelford has stated to agree with those of the 

 opposite sex, 1 we ! find to be much less specialized than in the 

 males and in the great majority of species useless as a diag- 

 nostic character. The subgenital plate is also generally simi- 

 lar in most of the species but in one before us, thalassina, it 

 is found to be very much more deeply concave mesad than is 



usual. 



OVERESTIMATED CHARACTERS. 



The width between the eyes is always less in the male sex 

 than in the female : the character is not of considerable help in 

 all or even many of the species, as Shelford has implied, 2 but 

 only in those in which decided differences in this feature 

 occur. On the whole, if slight differences were employed in 

 sorting series, these would prove not only unsatisfactory but 

 dangerous diagnostic features. 



In the female sex, some species have the transparent mar- 

 gins of the pronotum and tegmina much clouded or even 

 solidly opaque ; the males of these species show this condition 

 to a very much less degree or not at all. 



Minute dark brown dots are found on the tegmina in a 

 number of species. The number of such dots is individually 

 variable, and they are found both present and absent in indi- 

 viduals of the same species. Overestimation of the value of 

 the number and position of such dots has unquestionably led 

 to the erection of a number of synonymic names. 



DISTINCTIVELY MARKED SPECIES. 



In the species having the antennae annulate, the pronotum 

 with narrow lateral black lines, or other distinctive features of 



1 Trans. Ent. Soc. London, 1907, p. 463. (1908). 



2 Trans. Ent. Soc. London, 1907, p. 464, (1908). 



