Correlatio7i of Structure and Host-Relatiori 183 



sites are lumped, and those parasitic upon lepidopterous larva 

 occur together, although separated widely from those para- 

 sitic upon the eggs of the same order. 



And now as to the results of an examination of our Ameri- 

 can forms : 



It will not be necessary in this paper to go into detail as to 

 the structural peculiarities which have been found upon this 

 examination. They will be summarized elsewhere in connec- 

 tion with the descriptions of the new genera necessitated by 

 this investigation. The conclusions arrived at, however, are 

 as follows : 



Among the species parasitic upon Coccidae we find three 

 distinct t}rpes two of which will form new genera. The most 

 abundant is parasitic upon Lecaniina and Coccinae, the sec- 

 ond upon Diaspinse while a third and isolated type is reared 

 from a lecaniine — Pulvinaria innumerabilis. 



The species parasitic upon Aphididae possess a common 

 facies and form an independent type in the group distinguished 

 by well-marked structural characters. 



Among those parasitic upon Psyllidse we find an interesting 

 state of affairs. Those reared from gall-making Psyllidse be- 

 long to the same type as that reared from a gall-making ceci- 

 domyiid, while those parasitic upon nearly free-living Psyllidae 

 belong to two types, distinct from each other and from the 

 first, and dividing upon geographical lines, the one being east 

 coast and the other west coast. 



The parasites of the free-living dipterous larvae belong to a 

 common type distinct from the others, while that reared from 

 the dipterous gall-maker agrees in facies and in main struc- 

 tural characters with those just mentioned from psyllid galls. 



The species reared from a cynipid gall, however, forms still 

 another type and the most distinctly marked one of the whole 

 series. 



The species reared from lepidopterous larvae belong to a 

 common type, distinct from the rest, but most closely resem- 

 bling the forms reared from free-living dipterous larvse. 



Those reared from heteropterous eggs and those from lepi- 

 dopterous eggs belong to a common type and while separable 



