M 



ar., 1909.] ROHWER : CRYTOCAMPUS IN BOREAL NoRTH AMERICA. 9 



10. Stigma, except extreme base, black (venation usually normal ; apical antennal 



joint slightly shorter than the preceding one) bebbiance Roh. 



Stigma, except apex, pale 



II Apical antennal joint gradually tapering ; ocellar basin strongly defined ; lower 



discal cell of hind wings shorter than upper cooperce CV.\\. 



Apical antennal joint obliquely truncate ; ocellar basin not so strongly defined ; 



lower discal cell of hind wings longer than upper salicis-ovum Walsh. 



12. Length 3.5 mm. ; clypeus slightly emarginate .parvus Roh. 



Length over 4 mm. ; clypeus rather deeply emarginate salicis-nodiis Walsh. 



13. Clypeus entirely black ;* 



Clypeus with at least the apical margin pale ^5- 



14. All the femora black 



Some of the femora pale salicicola^. A. Sm. 



15 Legs below the coxae marked with brown ' • 



Lees below the coxse entirely reddish-yellow (apex of hind tibia; sometimes 



.17. 

 brownish) i/- a 



16 Stigma tapering to an acute point ; clypeus narrowly noichedjnsularts Kincaid. 

 Stigma not tapering to an acute point ; clypeus not deeply or narrowly notched. 



brachycarpcE Roh. 



18 

 17. Stigma entirely dark brown 



IQ. 



Stigma pale at the base "" 



18 Lateral ocellar furrows distinct, deep; antennal fove^e large .propmquus Koh. 



Lateral ocellar furrows not deep or distmct ; antennal fovese not s^^'j^^^.^^^^ ^^^^ 



19. Flagellum black (orbits black) p.rditns "^oh. 



Flagellum pale beneath ■"' ' 



20. Sides of abdomen above more or less pale salias-ovum Walsh. 



Sides of the abdomen above black •■••• • 



21. Flagellum entirely pale beneath salins-nodusW^Xsh^ 



Flagellum black basally •• ;"" " 



„ , , \ A macnlhvrayt Koh. 



22. t rontal crest notched * -' 



Frontal crest unbroken 



Table of Galls. 



An enlargement of the twig 



A lateral swelling on the twig • "••^' 



1. Enlargement abrupt at the lower end .prop:;ujuus Roh. 



Enlargement not abrupt at the lower end VV,V","\ ' 



^ ^,. , .... sa/uis-Tiodiis \\'a.\sh. 



2. Or\ Sahx longifoha 



marp-iilivrayi Koh. 



On Sahx luteosencea •^ 



4- 



3. Swelling elongate 



Swelling ovate or round V.:;;^^; N;.t; 



4. OnSalixhunuhs bebbian^ V.o\.. 



On Salix bebbiana . -o u ■> 



On Salix s^. (bark [dry] reddish) .propm.u.. Roh^. 



5. Swelling gradual 



Swelling abrupt.... 



