92 



After third Moult: lenoth .16 incli; color orey-oreen; shaj)e as be- 

 fore; straight hairs along" the ridge, curved ones around base; on seg- 

 ment 12, back of and between the stigmata, are two small swollen 

 yellow spots indicating the position of the concealed tubes, just as in 

 Pseudargiohis. To next moult five days. 



After fourth moult: length .25; two days later .36 inch; at five days 

 from the moult was fiill grown. 



Mature Larv.'K. — Length .44 inch; greatest breadth . 12 inch; slen- 

 der, of even width to near the ends, which are equally rounded, the 

 head being withdrawn into segment 2; segment 2 lies flat, the edges 

 thickened and rounded; the other segments rounded; the dorsum 

 rather high, rising to a flattened ridge, which is broadest on segment 3, 

 and narrows posteriorly to 10, where it ends; along either edge of the 

 rido-e are whitish bristles; around base a fringe of bristles; surface cov- 

 ered with short, fine, white hairs springing from black points; color of 

 one shade, a pale or whitish green; along base a cream-colored stripe; 

 under side blue-green; the tubes appear at will from segment 12, and 

 on II is an orifice on mid-dorsum, as in Pseudargiohis ; head small, ob- 

 ovoid, smooth, black-brown; the ocelli black. From fourth moult to 

 pupation eight days. 



Chrysalis. — Length .2<S inch; breadth across mesonotum .09 inch, 

 across abdomen .11 inch; abdomen broad, thence to head narrowing; 

 head rounded, blunt at top, narrow; mesonotum low, rounded, and 

 from top of this to head a regular slope; a slight excavation back of 

 mesonotum; color yellow-green, abdomen whitish; surface .-mooth, 

 glossy. Duration of this stage eight days. 



I received one larva of Melissa from Mr. H. W. Nash, of Pueblo, 

 Col., June 8th, 1883. The (t^'g had been laid on a leaf of an Astragalus 

 — pronounced by Prof (ioodale to be near bisulcatus-, but not enough 

 of the plant was sent to enable him to determine the species exactly. 

 The larva had just moulted when it reached me in the mail, and the 

 cast skin was by its side; length .25 inch. I aiterwards found the 

 moult to be fourth. I gave the larva blossoms of peas and clover, both 

 which it ate. The organs on segments 11 and 12 corresponded with 

 those found in larvae of Pseudargiolus and Comyntas. On mid-dorsum 

 of II was a transverse slit near the posterior edge of the segment, and 

 on 12 were swollen spots behind and between the spiracles. On June 

 9th I introduced a small ant to this larva, which was confined in a glass 

 tube. The ant soon discovered the lar\'a, and ran about it in great ex- 

 citement, caressing it with its antenna-. Immediately the tubes, which 

 I had not hitherto seen, began to play, and one or the other, or both 

 together, were exposed for some minutes, and indeed so long as the 

 ant was near. Sometimes the tubes were fully protruded, with the ten- 

 tacles ex])anded, at other times were partially withdrawn, in that case 



