32 2 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



ary sensoria narrow transverse or broadly oval, surrounded by 

 fringe of celia. 



The mesothorax with two wax pore plates. One on the inner, 

 posterior margin of each lateral lobe. The distance between them 

 usually less than the greatest diameter of the plates ; confluent or 

 separated by a straight line only in one species. 



Fore wing with M simple. Hind wing with media and cubitus 

 both present. Cornicles wanting. Cauda short, broadly rounded. 



Rudimentary gonopophyses, three. Sexuals small and beak- 

 less, females laying but one egg. Antennae five- jointed. 



Species live in curled leaves ; exposed on the twigs or stems, 

 or on the roots of the host plant. 



Key to Species. 



1. Secondary sensoria on joints iii, iv, v and vi of antennae of alate 



viviparous females 2 



Secondary sensoria on iii, iv and v only 6 



Secondary sensoria on iii and iv only 7 



2. Wax pore plates of prothorax and mesothorax distant 3 



Wax pore plates on prothorax, and mesothorax of alate viviparous 



females confluent or separated only by a line approximatus 



3. Normally twelve or less sensoria on iii 4 



Normally more than twelve sensoria on iii 5 



4. Joint iv of antennae subequal to front tarsi in length. Small 



species less than 3 mm. long. Wax pore plates well developed on 



base of head f raxinifolii 



Joint iv of antennae subequal to one-half the length of front tarsi. 

 Large species over 3 mm. long. Wax pore plates poorly devel- 

 oped or wanting on base of head tessellata 



5. Wax pore plates on mesothorax triangular in form venafuscus 



group (Sexuparae) 



Wax pore plates on mesothorax oval in form corrugatans 



group (Sexuparae) 



6. Secondary sensoria broadly oval to subcircular. Less than ten 



sensoria on iii imbricator 



Secondary sensoria narrowly oval to broadly linear. More than 



ten on iii corrugatans 



group (Fundatrigenia) 



7. Wax pore plates on head of alate forms subequal to or larger than 



those on mesothorax xylostei 



(Fundatrigenia) 

 Wax pore plates on head of alate forms distinctly smaller than 



those on mesothorax or entirely wanting venafuscus 



group (Fundatrigenia) 



The species of this genus are so little known and there is so 

 much confusion in the various collections regarding the naming of 

 some species that it is impossible to formulate a key for the sepa- 

 ration of all species. There are two groups for which this holds 

 true. One consists of the species venafuscus (Patch), fraxini- 

 dipetalae (Essig) and pyri (Fitch). The other contains the 

 species corrugatans and alnifoliae. 



Specimens labeled corrugatans (Sirrine) and alnifoliae (Wil- 

 liams) from Maine, Massachusetts, Illinois, Michigan, Colorado 



