550 Mr. C. L. Witliycombe's Notes on 



suitable support, often some feet up, and tlie imago is 

 disclosed. After shedding the pupal skin, the wings are 

 fully expanded in from ten to twenty minutes, and the insect 

 is ready for flight in considerably less than an hour after 

 leaving the cocoon. Emergence takes place in morning 

 or evening. If the temperature is less than 60° F., 

 emergence is often delayed for some days, though the 

 pupa is quite ready for emergence. A shiny black pellet 

 of larval excrement is deposited soon after the insect is 

 mature. 



The imagines are largely crepuscular or nocturnal in 

 habits. I have seen no spermatophore after pairing. 

 A female may live two or three months, if fed upon aphids. 

 Winter is passed generally as a larva within the cocoon, 

 as a free larva in C. wasina, veniralis and flavifrons, and as 

 an imago in C. vulgaris. 



Internal anatomy : — That of the larva calls for no special 

 comment. In the imago several points are of interest. 



Stink glands lie on each side of the prothorax, opening 

 just behind the head dorsally. These are green in life, 

 but when killed or exposed to air they become decidedly 

 bluish. The malodorous fluid secreted is pale yellow. 



The salivary glands, passing back along the sides of the 

 oesophagus to the hind part of the prothorax, are then 

 recurrent, and just behind the head, branch into tufts of 

 diverticula which intertwine with diverticula of the opposite 

 side, over the dorsal part of the oesophagus. The simplest 

 form of tuft is seen in C. se])tempunctata and vulgaris 

 (Plate XXXIX, fig. 10). At the extremity of each sahvary 

 gland are two main branches, and each of these subdivides 

 into three short diverticula. In C. alba, tendla, j^rasina 

 and verdralis the glands are of the same pattern, but 

 the diverticula are longer. In the remaining forms 

 (Plate XXXIX, fig. 11) the diverticula are very long, and 

 often branched, — C. flava, flavifrons, perla, and N. capitata. 



The testes are always separate and each enveloped in a 

 yellow scrotum. The general outline is elliptical, pointed 

 somewhat at each end. The following modifications occur. 

 C. flava (Plate XXXIX, fig. 12), testis elliptical, slightly 

 pointed; vas efierens leaves from posterior end. C. alba 

 and psrla (Plate XXXIX, fig. 13), testis as in flava, but 

 vas efferens leaves from anterior extremity. N. capitata 

 (Plate XXXIX, fig. 14), testis elongate with one twisted 

 lobe posteriorly; anterior vas efferens. C. vulgaris, testis 



