IOO 



MELANDER. 



The fortunate discovery of all the forms of the American spe- 

 cies reveals the [fact that the Embiidae may be polymorphic. 

 During the winter and spring our species exists in the larval 

 state, with occasionally a chance female surviving the summer 

 and living into the autumn in the same nest with her young. In 

 early May the final moultings occur. At that time the larvae 

 destined to become females increase rapidly in size, and with the 

 final moult their reddish mottled color becomes a dark chestnut 

 brown or even a bronzed black posterior to the prothorax. No 

 traces of wings are evident nor is there a lengthening of the an- 

 tennal joints. The abdomen of the female retains the symmetri- 

 cal termination of the larva, is covered apically with longer and 

 denser hairs, the last ventral becomes longitudinally split, and 

 the cerci remain each two-jointed and short. These large females 

 are sluggish in movement, carrying the abdomen with a dorsal 

 hump as does the larva. They still spin their web-nests with 

 glands unaltered during their metamorphosis. They are often 

 social and frequently live two or three in a nest, whereas but a 

 single male develops out of a brood of larvae. The same fact 



FIG. i. Male. Tip of abdomen, and base of antenna. 



has been observed in the case of insularis. However, in all col- 

 lections of the Embiidae the females seem to be much the rarer 

 sex. 



With the male the metamorphosis may proceed in one of two 

 ways, i. e., the males of tcxana, and of other species also, are 

 dimorphic. At the penultimate moult wings may be formed, as 

 in the Orthoptera, or not. In the former case a true nymph- 



