I'AMnilMDI: THE GENUS ATRYTONE. 1609 



Caterpillar at birth, lloiul lnr.i;c, consi(li;ral)ly liigUor llmii broad, bromlest below 

 the iiiklilli', mirrowly and roi^iilarly rouiulcd above, with scarcely the least depression 

 at the suture ; trianiilc considerably Idpihcr tlian broad, reachlui; above the middle of 

 the head ; special papillae, bearing lonj;, delicate liairs, are found outside of ttie 

 triangle, on either side, just above its summit and somewhat above tlie middle, as also 

 oilier lateral hairs in the ocellar Held, at ttie widest point of tlie head and less than 

 midway between tins and the summit ; ocelli forming a curvinj; row, four in iuiinl)cr, 

 equal, equidistant; tlurd antcnnal joint half as long again as broad, cylindrical but 

 arcaate. 



Body slender, equal, tapering apically; the dorsal tlioracic shield narrow, situated 

 on tlic anterior portion of the segment, bearing distant, erect or forward curving, 

 tapering liairs; segments of the body apparently divided into five subsogments, of 

 •which tlie anterior is as large as tlic remaining together, and tlie first of the smaller 

 ones a little larger than the others ; bristles scarcely tapering, scarcely enlarged 

 apically, erect, about half as long as the segments, arranged in longitudinal rows, tlie 

 position of which lias not been determined, but some of the bristles are anteriorly, 

 some posteriorly placed ; terminal segment with three pairs of very long, recurved 

 bristles at the middle and posterior end of the segment, besides two pairs anteriorly 

 placed, of shorter, simil.ar bristles, all appai'cntly in the subdorsal series. 



Mature caterpillar. Head subglobose, well rounded, broadly rounded beneath, 

 strongly and regularly arched above, where the curve is scarcely interrupted by a 

 slightly incised suture ; broadest just above the ocelli, of aliout equal breadth and 

 height, depressed below, narrowing very gradually above, slightly protuberant in 

 front, below; triangle distinct, the inner one terminating in the centre of the head, 

 half as high again as broad, regular; ocelli six in number, five arranged in a regular, 

 arcuate curve, the lowest directly outside the base of the antennae or slightly farther 

 back, as far removed from the fourth as the fourth from the second; the first four 

 subequidistant, all of these subequal; the sixth smaller, directly above the fifth, form- 

 ing with it and the third the angle of a rectangle. 



Body plump, cylindrical, tapering slightly on the thoracic segments and behind the 

 sixth abdominal segment; first thoracic segment with an obscure tlioracic sliield, 

 deeply and transversely sulcate, not reaching the spiracles by the length of the latter; 

 followed anteriorly by a naked space, and then abruptly descending to an excessively 

 short collar; anal plate of the last abdomin.al segment broadly rounded, sulitruncate; 

 segments divided very obscurely into seven subsegments ; the first and second faintly 

 separated from each other, as well as the sixth and seventh ; th-e first and second 

 together more than equalling the three following in length; studded profusely with 

 excessively minute papillae, bearing equal, short, delicate, erect liairs, forming a pile; 

 inferior gland of first abdominal segment obscure, transverse; thoracic legs rather 

 feeble; abdominal legs not so stout as usual ; there is a central lateral series of ex- 

 ceedingly minute, crateriform disks, transversely oval in shape, those of the second 

 and third thoracic segments single, lower than on the other segments, that on the sec- 

 ond directly at the upper edge of the thoracic callosity; the first thoracic segment has 

 also a pair midway betsveen the spiracle and the legs, or a little nearer tlie latter; a 

 suprastigmatal and infrastigmatal series of the same, the former transversely oval, 

 the latter circular and slightly larger, situated as far behind, as the suprastigmatal 

 series is in front of, the spiracles; and a lateroventral series of transverse, broad, 

 oval or circular disks, as large as the spiracles, on the apodal abdominal segments. 



Chrysalis. The specimen of A. zabulon, upon which I had intended to base the 

 description of the genus having been lost, I have only a few fragmentary notes. The 

 free portion of the tongne lies close to the body, and reaches as far as tlic middle of the 

 seventh alxlominal segment, the wings as far as the middle of tlie fourth segment ; the 

 prothoracic spiracle is prominent, ovoid, edges slightly raised, transversely furrowed. 



This genus of butterflies is peculiar to eastern North America, extending 

 over the whole of the United States lying east of the Rocky Mountains. 



