1879.] 221 



ported by a narrow, white membrane or ligament, about one-tenth 

 ineb long, one end of wbicb is pointed and fastened to tbe inner side 

 of the larval skin near the extremity thereof, and the other is forked 

 and fastened to the ends of two curved, slightly raised, longitudinal 

 ridges, which are to be found on the ventral side of the last segment. 

 These ends are at the anterior edge of the segment. They project 

 sufficiently to form hooks, as it were, which hold the membrane firmly. 

 In ArcJiij)ptis the ligament is much larger and stronger than in Grapta. 

 It is broad, black, and deeply forked where it attaches to the segment. 

 In this species, instead of low ridges, there are two rows of shining 

 black processes, three in each row, and the outer pair are knobbed, 

 and a little pointed anteriorly. On these outer knobs, the ligament is 

 fastened. I do not believe that the chrysalis of Grapta ever seizes 

 the loosened skin for a support — at any rate any support that such a 

 hold could furnish is not essential, for I have repeatedly raised the 

 skin with forceps entirely off the abdominal segments on the ventral 

 side, so as to discover the distended membrane, and in several cases 

 have cut the skin off just below the membrane at the instant the effort 

 was beginning, for freeing the tail. In these last cases the chrysalids 

 were seen to be connected with the skin by the membrane only, and 

 the membrane is the lever by which the chrysalis climbs to the silk. 

 There could not possibly have been any other support. 



Reaumur's account of the pupation of the Suspensi was drawn up 

 after very extended observations on larvae of several species of Vanessa 

 principally (he says, several hundred caterpillars), and is given at great 

 length. Similar statements are given by subsequent authors, often 

 based on direct observation, but so far as I can discover, one and all 

 describe the process as it would appear to a looker on. I noticed in 

 "Westwood and Humphrey's British Butterflies, p. 54, what is doubt- 

 less an inadvertent error :• — ^" The chrysalis carefully withdraws its tail 

 from the skin, seizing hold of the outside of the latter by pressing two 

 of the rings of its body together, and enclosing between part of the 

 old skin. By repeating this process, it at length pushes its tail up- 

 wards, till it reaches the silken button," &c. For outside, read inside. 



Dr. Harris, Ins., 2nd ed., p. 2S2, gives an account of the trans- 

 formation of Archippus with much detail. 



" By bending together two of these rings near the middle of the 

 body, the chrysalis seizes, in the crevice between them, a portion of 

 the empty skin and clings to it so as to support itsef v:lai\e it withdraws 

 its tail from the remainder of the skin. It is now wholly out of the 

 skin, to ivhich it hangs suspended by nipping together the rings if its 



