244 [October, 



a small black mark in the region of the ocelli. (Pronotum, tegulae, 

 legs, and about five abdominal segments, red. Wings with a large 

 fuscous or yellowish cloud over their discs, generally' very conspicuous 

 in the $ , less so in the <J) betulce, L. 



3 (2) Abdomen above marked with red 4. 



Abd. above without red markings. (The $ has the head, pro-, and meso- 



thorax, ochreous with large black markings. The legs are ochreous 

 with femora black within. The abdomen is black above, yellow at the 

 sides and beneath. The J has the head [except the face] and the 

 thorax nearly entirely black, the abd. and legs as in the other sex)... 



silvarum, 8teph. 



4 (3) Mesonotum black, with only scutellum and tegulae yellow. Head above with, 



at uiost, a small spot, or a narrow longitudinal streak from eye to 

 occiput, yellow 5. 



Mesonotum and liead with conspicuous yellow markings besides those above 



mentioned 6. 



5 (4) S with head much narrowed behind eyes ; 3rd ant. joint more than twice as 



long as 4th ; all dorsal segments of abd. after the 1st with black bases 

 and reddish apices ; venter pure yellow : 9 with a long yellow streak 

 from eye to occiput ; intermediate dorsal segments of abdomen with 

 only short and narrow discal streaks of red ; ventral segments with 



black bases and yellow (not red!) apices balteatus, Fall. 



(= cingulatus, C). 



(J with head little narrowed ; 3rd ant. joint only twice as long as 4th ; red 



on dorsum of abd. forming a single broad band (occupying two segments 

 completely and part of another), the remaining dorsal segments black j 

 the ventral reddish : 5" with only a small yellow triangle between eye 

 and occiput (no long streak) ; segments 2-4 of the abd. practically red 

 throughout both dorsaliy and ventrally ; the following segments quite 

 black (no yellow apices to their ventral plates!) hortorum, King. 



6 (4) Space between ocelli and antennae, as well as the rest of the head and thorax, 



largely and conspicuously marked with yellow; dorsum of abd. largely 

 and brightly red depressus, Schr. 



Space between ocelli and antennae black. Altogether a darker insect than 



depressus, with less yellow on head and thorax, and the red of abd. 

 duller ; also the 3rd ant. joint is a trifle shorter pallipes, Zett. 



7 (1) Scutellum yellow ; abd. with red and lacteous markings... 



stramineipes, Htg. 

 (= arbustorum, C). 



Either the scutellum is without yellow, or the abdomen is unicolorous 



(violet-black) 8. 



8 (7) Abd. with broad red band occupying about four segments ; scutellum black ; 



stigma particoloured (yellow base and dark apex !) inanitus, Vill. 



Abd. entirely violet-black ; scutellum yellow ; stigma fuscous throughout 



(not yellow at base !) silvaticus, L. 



