"^1-i [November 



placed immediately behind the black pencil on the 11th segment, and often 

 •with a few long black hairs above it. Besides the pencils, there are also some 

 long, irregular, whitish hairs projecting forwards over the head and backwards 

 over the anus. Legs and prolegs very pale ferruginous, slightly obfuscated at 

 tip. — When much less than half-grown, the head is generally not black but 

 rufous, the black pencil on the 2ud segment is often only slightly tino-ed with 

 black, and the pencils on the 11th and 12th segments are occasionally subobso- 

 lete or all whitish and untinged with black Food-plants, oak, basswood, elm. 

 &c ; very common near Rock Island, Illinois. 



I am not perfectly sure that the hirva of tessellaris has white pen- 

 cils under its orange-colored ones, as Antqihola has under its black 

 ones ; but unless my recollection of last year's specimens deceives me, 

 it has. Harris however makes no mention of any such white pencils, 

 and the only specimens I was able to procure in 1SG4 had their pen- 

 cils so mutilated, that it was difficult to decide the question from them 

 with absolute certainty. In Illinoian specimens of ti-.-ixfJlark it will be 

 recollected, that the color of the tufts that cover the body above is 

 white, and not dark as in almost all Antiphda ; and consequently in 

 mutilated specimens it is difficult to distinguish the white pencils from 

 the white tufts. It may be incidentally remarked here, that in Illinois 

 tessellarin appears and disappears several weeks before Antipliola. 



It will thus be seen that, so far as known at present, the only^:»er- 

 fectli/ constant character that distinguishes the larva of tcssellnris from 

 that of Antiphola^ is the color of its pencils being orange instead of 

 black, and its food-plant being sycamore instead of oak, basswood, &c. 

 Out of hundreds of Antiphola that have passed through my hands, 

 there was indeed a single specimen, apparently freshly-moulted, as the 

 pencils were incurved at the tip instead of being straight, that had 

 those pencils white which ought to have been black ; but on placin'^- it 

 in a breeding-cage, I found that the next day they had changed to 

 their normal color, although those on the 2nd and 11th segments were 

 much paler than usual. This was the same specimen before referred 

 to as having changed its general color in confinement from white to 

 gamboge yellowish. 



If the pencils themselves in these two forms had been located on 

 different segments, as in the first instance I had wrongly supposed, 

 there could have been no doubt of the specific distinctness of the two, 

 the difi"erences being structural ; but as the two forms only differ in the 



