502 NOTES ON LACITNOSTEItNA. 



so variable and vet so strangely similar thai alter arranging a series to 

 show all the differences in habitus, color, and other details in the 

 strongest light, another series can be built up of precisely the same 

 specimens to show that there is only one form. 



The latter conclusion was the one arrived at by Dr. Horn in his study 

 of fusca, and he pointed out both the differences that had been considered 

 specific and racial, and the reasons for still considering them forms of 

 the same species. Dr. Horn also pointed out some of the differences in 

 the ventral characters, but considered them -within the limits of varia- 

 bility, if even of varietal importance. The misleading character of the 

 aggregation consists in the fact that all the species into -which I have 

 divided it vary in precisely the same manner, so that it is easy to ob- 

 tain a series of specimens almost identical in all characters save those 

 of the ventral segments of the male, and which yet represent at least 

 six different species. Still Br. Horn left the question somewhat un- 

 settled, and open to future consideration. In the course of our collect- 

 ing we first noticed the remarkable constancy of the ventral characters 

 of the males of the species, or rather form of fused taken by us, and from 

 this began to consider that it might refer to a distinct species. When 

 finally my attention was directed to the genitalia the suspicion became 

 a certainty, and the true solution of the fusca problem became evident. 

 The males, it was found, were thus easily to be separated; the females 

 were in a different case ; here there were no anal or ventral characters, 

 and little or nothing in the way of superficial differences. An exam- 

 ination of the primary sexual characters showed, however, that the co- 

 relation found in the other species existed here as well, and that the 

 species were well marked in both sexes. 



In No. 6 of Insect Life I showed some of these differences, and gave fig- 

 ures of the characters relied upon. Since that time three other species, 

 each coming under the definition of fusca, have developed. Of these, 

 one was rather a surprise to me, coming from a region supposed to be 

 well represented in local collections, viz, Snake Hill, New Jersey, while 

 the others represented forms not seen by Dr. Horn and which would 

 have been most probably recognized as distinct by him. The table of 

 species allied to fusca as given in Insect Life must therefore be modi- 

 fied, and as the group fusca in the restricted sense becomes so much 

 changed, a new table of the species is given. 



I wish again to emphasize the fact already mentioned in Insect Life, 

 that 1 have made no effort to identify the species here separated with 

 the types described by previous authors. I simply had neither the op- 

 portunity nor the knowledge of types to enable me to do it. If, at some 

 future time, older names will be identified with my species, I am content 

 to drop my terms, believing that in defining the species I will have dis- 

 armed blame for the needless names, if they bo such. 



The following table includes all those species which agree in the char- 



