THE CANADIAN ENTOMOLOGIST. 337 



and prolegs gray. A sublateral row of short setae. A rather strong 

 mid-dorsal, blunt tubercle over the third pair of prolegs. A rather 

 strong double tubercular ridge over the 8th abdominal segment. . 

 Head flattened in front, gray with yellow, cara-Vike spots at upper 

 lobes (of the head), bounded outside by a black dash. 



May 20th — Larvae just after moult, one and one-half inches long, 

 light bluish gray with light brown tubercles and light brown pro- 

 legs and cross-dorsal patches on the 5th and 8th abdominal 

 segments, of the same colour. Head dished in front with light 

 brown lobes above, and outer bounding black dash. A strong 

 tubercle on dorsum of 5th abdominal segment and a pair of 

 lesser tubercles on dorsum of the 8th abdominal segment. All 

 three of these tubercles are brown, the one on the 5th with 

 whitish tip. True legs gray. Sublateral row of short setae. Pro- 

 legs rather long. 



~ May 23rd — Larvae full grown, two and two and one-fourth inches 

 long, ashen (the exact colour of the gray branches of bur oak). 

 The strong tubercle over the 5th abdominal segment, the pair of 

 strong tubercles over the 8th abdominal segment and the roughness 

 of body, due to the other tubercles, give a strong case of mimicry 

 (like the knotty twigs of bur oak). 



The general body tubercles yellow-brown, as also the dorsal 

 pair over the 8th abdominal segment, but the latter are set on a 

 bifid ashen ridge. The tip of the tubercle over the 5th abdominal 

 segment has the body colour, but a little lighter at the tip. En- 

 closing and extending downward to the ventral surface from the 

 5th abdominal dorsal tubercle is an irregular band of brown and 

 a similar patch either side of the 8th abdominal dorsal ridge. 



A sublateral row of short setae. Head as in cara, bifid above 

 with lighter lobes flanked outside by a black dash. Ventral side 

 pole pifik with strong central black spots. There is a slight white 

 patch either side of the first abdominal segment. 



Larvae began spinning May 27th. Just before spinning the 

 larvae evacuate a bright red fluid. 



The first imago was on June 17th. Pupal period, 15 to 18 

 davs. 



