THE STATE ENTOMOLOGIST. 21 



Cicada, hitherto confounded with septemdeeim, and was named Cicada 

 cassinii. His description was followed by a note from Mr. John Cas- 

 ein, in which he states that the two forms show no disposition to asso- 

 ciate together, and produce very different cries. The fact of the very 

 great difference in the song of the males has been fully confirmed by 

 the observations of M. C. Hill, of Northeast Ohio, who likewise found 

 that the small form is very much less numerous than the large one. 



The truest test of the specific distinction of these two forms lies 

 in the comparative shape of the male genital hooks, and on submit- 

 ting specimens of both forms to Dr. H. Hagen, of Cambridge, Mass., 

 formerly of KGenigsburg, Prussia, he very kindly furnished the draw- 

 ings e, d, e, and f, in Figure 6, which show the male genital hooks of both. 

 That of septemdeeim is represented on the outside at c, on the inside at 

 d ; and that of cassinii on the outside at e, and on the inside at f. 



By these figures, it will be seen that there are sufficient differ- 

 ences to separate the two forms as distinct ; but while the hooks of 

 ihe large kind (septemdeeim) are quite constant in their appearances 

 those of the smaller kind (eassinii) are variable, and in some few 

 specimens are undistinguishable from those of the large kind. This 

 circumstance, coupled with the fact that the small kind regularly oc- 

 curs with both the 17 and 13-year broods, would indicate it to be a 

 dimorphous form of the larger, or true periodical species; especially 

 when we consider that dimorphism and heteromorphism are not un- 

 common among the true Bugs (Hemipteea). Mr. P. K. Uhler, of Bal- 

 timore, Md., who has given this order of insects particular attention, in- 

 forms me that he is not fully satisfied of the specific distinctness of 

 €. eassinii ; but Dr. Hagen thinks there is no possible doubt of its 

 being distinct, for the simple reasons, as he states, that dimorphism 

 occurs only in one sex, while here both sexes are involved; that 

 cassinii appears later, makes a different noise, has different colors 

 and was never seen to copulate with septemdeeim. To use Dr. Ha- 

 gen's own words, " what more is needed to make a distinct species , 

 if one kind of Cicada requires 17 years to undergo its transformations, 

 why not a second kind ?" I find among a great number of specimen, 

 which I have examined, that not only do the hooks of cassinii vary, 

 but the other characters that have been mentioned as belonging to 

 it, are variable, there being perfectly intermediate grades between its 

 extreme type and that of septemdeeim. Again, on the supposition 

 that it is a distinct species, the chances are extremely small, of its is- 

 suing together with septemdeeim in the same year in the many differ- 

 ent localities hereafter mentioned. Therefore, though it will be con- 

 venient to use the two names, I think the two forms should not be 

 ranked as distinct. But the discussion of the subject would involve 

 the general problem of specific character. 



The large species has been observed to make its appearance from 

 eight to ten days earlier than the small species (cassinii), and there 

 is not a single specimen of the latter, among a number of the 13-year 



