( xi ) 



this one species of Trichaulus only ; now I have found ihe 

 females of Critoyaster piUventris and C. mulu also. In these two 

 species there are at the same time winged and wingless males, 

 the latter being by far more numerous; of C. iiuda I found one 

 winged male to about ten females ; of C. piUventris I have met 

 with but one winged male among hundreds of females ; of C. 

 svu/iilaris {Trichaidus versicolor), though this is by far the most 

 common species of the three, I have seen none. 



•' Physothorax disciger is the wingless male of Diomorus 

 variahilis. Diomorus produces very large galls, not connected, 

 as far as I can judge, with the flowers of the fig. From these 

 galls I raised numerous females and winged males of Diomorus, 

 a few Physothorax, and one extremely curious male, intermediate 

 in any respect (colour, antennae, wings, &c.) between the winged 

 males of Diomorus and the almost wingless PJnjsothorax. I may 

 add that the structure of the hind legs and of the genital armature 

 of the male is quite the same in the two forms. The wingless 

 males (Physothorax) are incomparably less frequent in this 

 species than the winged ones. 



"As Plesio stigma hicolor, of which G. Mayr described winged 

 males, is nearly allied to Diomorus, I think it to be rather 

 probable that Physothorax annuliger should be the wingless male 

 of this species. I did not see, this year, either of these two 

 forms ; perhaps they may be only aberrant forms of tlie poly- 

 morphic Diomorus variahilis, of which I have even seen two 

 wingless females. 



" Nannocerus biarticulatus is the wingless male of a Diomorus, 

 distinguished from D. variabilis by its ovipositor being shorter 

 than the body, while it is considerably longer in D. variabilis. 

 The galls, of which 1 have seen but very few as yet, are peduncu- 

 lated, while those of D. variabilis, of which I have gathered more 

 than 800, are always sessile with a broad basis. I have not yet 

 seen the winged male of this Diomorus. 



" Of the genus Heterundrium G. Mayr describes two species of 

 wingless males [H. longipes and H. nudiventre), which he could 

 not refer to any female. Now H. longipes is the wingless male of 

 Colyostichus longicaudis, and H. nudiventre that of 0. brevicaudis. 



" Thus we have among the tig-insects of the Itajahy at least 

 seven trimorphic species, consisting of females, winged and wing- 

 less males, viz., Critogaster nuda, C. piUventris, Diomorus varia- 



