214 ORDER LEPIDOPTERA. 



eyelet being in the middle : the anal angles divaricate, leaving a wide triangular 

 space. 

 This species was first described, I believe, by the Rev. Mr. Kirby in the Fauna Boreali 

 Americana. 



Lycsenidae. 



LYCiENID^ ( Leach). POLYOMIVIATID^ ( Swainson). 



The insects of this family are small and weak, but finely and delicately colored and 

 marked. The forelegs are fitted for walking, and the last joint of the palpi is small and 

 naked. The caterpillar has a small head nearly concealed under the first ring, and secures 

 itself, when about to undei^o transformation, by the hindfeet and a loop about the body. 

 The chrysalis is flat on the underside ; its ends are round : the imago six-footed. Social, 

 and often collected into groups upon sweet-scented flowers. 



Thecla acis. ( Plate xliii, figs. 2, 3.) 



PoLYOMMATUS ( Latreillc & Godart). Papilio acis ( Drury). P. ixion ( Fabricius). 



Superior wings immaculate and dark brown above, paler beneath : posterior, blcaudate ; 

 the two inner the longest, and immediately above are two red spots, and two more 

 upon the anal angle. Under side, the wings are lead-colored, crossed by a narrow 

 white and black line running parallel to the external edges ; the ix)sterior are crossed 

 by an indented irregular line : the four long reddish spots stand above four black 

 ones. 



Thecla humuli ( Harris). 



Anterior or primary wings dusky brown on their upper sides, tinted with bluish gray j 

 and, in the males, they are also marked with an oval spot on the front edge. The 

 posterior wings are slenderly tailed, but, unlike those of the acis, they are tipped wilh 

 white ; and the margin posteriorly is also marked by a row of pale blue spots, among 

 which is a crescent of orange marked in the centre with a black dot. It is a little 

 larger also than the acis ; expanding about an inch and a tenth, while the acis is only 

 about an inch. 

 In its caterpillar state, the T. humuli feeds upon the heads of the hop, as is implied by 



its specific name : its color is green, and its skin is downy. Described by Harris in his 



work on insects injurious to vegetation, p. 235, 2d edition. 



