IO4 MELANDER. 



single nest, which often would contain several females. In color, 

 size and structure both forms of the males are exactly similar. 

 Moreover, they have the same movements, with forelegs elevated, 

 though the wingless male generally carries its abdomen curved 

 further over the back. Their only difference is in the matter of 

 wings. 



In the Entomologists' Monthly Magazine (1897, p. 56), Mr. R. 

 C. L. Perkins notices a peculiar condition of the thorax of Embia 

 insularis. From the hinder angles of the meso- and metathorax 

 project small lobes which he concludes are the beginnings of the 

 wing-pads at the stage immediately preceding the nymph-form. 

 A specimen of a full-grown wingless male of texana presents the 

 same peculiarity. This cannot be explained as a case of atavism 

 an attempt at the wing-formation which this form has lost- 

 for the true wings arise from the anterior angles of these seg- 

 ments and hence are not homologous with these free lobes. 

 Moreover, we have sectioned the fully-grown larva and find the 

 wings as large invaginated pockets completely beneath the hypo- 

 dermis. 



The males of Solicri seem undoubtedly all to be wingless, 

 although the evidence rests largely on the absence of winged 

 forms. Professor Grassi and Dr. Sandias obtained numbers of 

 mature wingless males but none with wings. However their 

 observations were interrupted during July to September. 



The structure of the anal cerci of the Embiidae varies with the 

 individual. The males of three species (tartara, texana and 

 Whcclcri} have the left cercus always single-jointed and the right 

 one two-jointed. As far as can be judged from the descriptions 

 all the other species (except possibly mauritanicd) have both ap- 

 pendages two-jointed in the male as \vell as in the female. It is 

 among this latter class that the structure of the cereal joints 

 varies. 



Herewith is appended a table of all the described species of 

 this family, indicating the extent of polymorphism as far as has 

 been recorded. The localities of distribution are added to ac- 

 company the map given later on. 



