[79] NOTES ON NOTODONTA DICTCEA. 191 



enigma to me, to the imago which they produce, which is ap 

 parently identical with the Notodonta dictcea of Europe. 



T regret that I have not at hand a detailed description of 

 the European larva, to compare with our own. Stephens 

 (Illustrations of British Entomology, Haust. II., p. 25), says 

 of it: &quot;Larva naked, with a small conical protruberance on 

 the anal segment ; reddish-brown, green on the sides and 

 glossed with violet above, with a black dorsal streak : it feeds 

 on poplar, willow and birch, and is found in July and 

 September.&quot; 



Newman, in his History of British Moths, page 228, gives 

 the following description : The caterpillar has rather a large 

 head, which is very slightly notched on the crown and shin 

 ing, and is of a pale green color. The body is almost uni 

 formly cylindrical until the twelfth segment, which is humped, 

 and the hump terminating in a moderately sharp point ; the 

 color of the body is whitish or glaucous -green on the back, 

 with a broad paler green stripe on each side and adjoining 

 this there is a narrow raised yellow-green stripe, just below 

 the spiracles, and touching all of them except that on the 

 twelfth segment ; it extends the entire length of the caterpillar, 

 terminating in the anal claspers; on the summit of the twelfth 

 or hump segment, is a black transverse line. It feeds on the 

 sallow (Populus nigra), etc. There is a common variety of 

 this caterpillar which is plain brown, without the slightest 

 appearance of the lateral stripe; this occurs after the last 

 change of skin.&quot; 



Dr. Speyer writes of the larva of the European N. dictcea : 

 It has a tubercle of pyramidal shape on the llth segment, 

 which is much more pointed in the younger stages of the larva, 

 so as closely to resemble the horn of a Sphinx. The mature 

 larva has a strong porcelain lustre, and occurs in two varie 

 ties : one is of a green color with a yellow stripe on its sides, 

 and the other is brown without the stripe. It lives on poplar. 



Several examples of the American N. dictcea were sent by 

 Mr. von Meske to Dr. Speyer to compare with the European 

 forms. Having made the comparison, he does not doubt that 

 they are identical, although the following differences are no 

 ticeable. &quot; The American form has a bent white cross-line on 

 the inner part of the brown portion of the anal angle of 

 the secondaries, which is not found in the European. In the 

 former the interior branch of the median nervure [vein 2] has 



