344 TRANS. ST. LOUIS ACAD. SCIENCE. 



traction. It is within the hidden base ot this elastic funnel, or just 

 above the burrow proper, that the pupa state is generally, if not 

 always, assumed. A more careful study of Yucca tops in which 

 the pupa was naturally formed — i.e. in plants not cut till after 

 pupation — shows me, also, that the partial closing of the bur- 

 row near head and tail is due solely to the elasticity of the funnel. 

 No additional silk is used, and nothing that can well be called a 

 cocoon is constructed. Just above the natural contraction that 

 occurs at the junction of the more elastic with the more firm and 

 solid portion of the burrow, the pupa rests — the cast-off larval 

 skin generally helping to close up the lower passage. Here the 

 pupa has perfect freedom of motion, and readily twirls the lower 

 part of the body when disturbed. The natural recurvature of the 

 abdomen, as shown in the figure, presses the bristled, dorsal and 

 terminal portion of the body on the one side, and the ventral, 

 middle portion on the other, against its elastic confines, and holds 

 it securely. A few muscular movements, aided by the leverage 

 and hold which the aforementioned bristles insure, bring the 

 pupa, when the imago is about to issue, toward the top of the 

 funnel, which readily opens under the pressure, since it is closed 

 only by contraction. In the issuing of the imago the pupa re- 

 mains within the tube. 



Having recently (March 13) let several of the butterflies loose 

 in a spacious chamber in order to watch their movements, I can 

 confirm what has been said of the rapidity and strength of their 

 flight. I would further add, that, in resting or walking, as in all 

 their actions, they have the characteristics of the larger-bodied 

 skippers. When the wings are not used in flight, the inferior 

 portion of the secondaries is folded along vein 1 and tucked in 

 under the submedian, as is, I believe, the case with all Hesperians. 

 At rest, the outer portions of primaries are brought more closely 

 together than my Fig. 29 indicates. The favorite position of the 

 insect when at rest is vertical, or even hanging from beneath an 

 oblique object. In walking, the wings open more or less, but the 

 hind ones are not held horizontal. In walking on a flat surface, 

 the fore body is strongly raised on the legs, while the end of the 

 abdomen, especially in the female, generally touches the ground, 

 so that the costae of primaries are nearly on a plane with the sur- 

 face. The antennae are most often on a plane with the body, and 

 strongly diverging. 



