THE POSITION OF PSEUDOPONTIA (gONOPHLKBIa). 215 



meet again in the Lycaenidae. But what we consider as a very 

 strong corroboration of oiu' view is the fact that vein IVi ascends 

 the radius. Not only this, but vein IV, foUows suit, an extraordinary 

 culmination of the Fierid movement. Only vein lV.s remains attached 

 to the crossvein, which closes the cell. As in the Pierids, the cell is 

 closed, and we see no movement to open it, through a degeneration of 

 the crossvein, as in the Nymphalids, in which latter the upper branches 

 of the median series never ascend the radius. It remains to be stated 

 that vein VIII of primaries forms a loop, as in the Hesperiades, 

 among which I would place the family, considering it as a curious and 

 moditied survival of the ancestral Pierid butterflies, and having nothing 

 at all to do with the Papiliones, with which Reuter associates it. 

 The characteristic of the Papilionides is the presence of veui IX 

 on primaries, wanting in Gonophlehia. 



The structure of the Spiracles in Lepidoptera. 



By T. A. CHAPMAN. M.D., F.Z.S., F.E.S. 



So far as I have been able to observe, the structure of the spiracles 

 in Lepidoptera at all stages is the same as that exhibited in the obser- 

 vations described ante, pp. 185-188, viz., an inner true valve capable 

 of movement by a special muscle or muscles, by means of which the 

 opening may be aljsolutely closed. Outside this, at a distance of about 

 the diameter of the tulje, an outer false valve, that which we ordmardy 

 call the " spiracle." I say /ft/se valve, since, though this is often called 

 and described as a valve, it has no movable parts, and is really a 

 grating, screen or sieve. This may be seated on an eminence, or more 

 usually'is on a level with the integument, or may be at the bottom of 

 a hollow, as noted in the pupa of Phtdera bncephala, or deeply 

 between the segments, as in the thoracic spiracles of many imagines, or 

 especially as in the thoracic spiracle of nearly all pupse of Lepidoptera. 



The external valve is described as l)eiug really a valve with one 

 side or plate movable. I think this is certainly not so m lepidopterous 

 pupcV3 at any rate, where this outer valve is simply a narrow chink in 

 most species, a circular, oval, or trefoil opening in others, with dendritic 

 processes so disposed as to act as a sieve or screen, but without any 

 movable or articulated portions. It may be noted that the outer 

 valve has such a sieve-like open structure, that its closing could not be 

 of any air-tight valvular nature, even if it had any movable parts. Nor 

 can I find any valvular arrangement within the eyelid-like valve, 

 such as Lowne figures as existing in the abdominal spiracles of the 



blowfly. • X X- i.- 11 



Whether the outer, and this third inner, valve exist tunctionally 

 or no in other stages of Lepidoptera, which, however, I very much 

 doubt it is certain that the valves I see at work in the newly changed 

 pupa,'and which are I think certainly those usually called the inner 

 valve's, have some definite function to perform at that stage of the 

 insect,' without assistance from any other valvular structure. The 

 alteration of the rhythm of their movement during the short period 

 that the observation lasts, viz., the gradual lengthening of the period 

 duriuo- which they are closed, suggests that possibly during the moulting 

 and tile preceding period of rest they have been, if not unduly stretched, 



