COMMON BUTTJERFLIES OF THE PLAINS. 75 



gently concave. The colour is a fine rich grass-green, rather bright, with a 

 broad, white dorsal line generally showing the transverse lines of the seg- 

 ments (the 7) as slight depressions throughout its length; this dorsal line 

 often reaches from the anterior margin of segment 2 to the anal flap, some- 

 times it is more or less indistinct but generally present on the first few 

 segments ; there is, besides, sometimes, a fine light, very thin, spiracular 

 line ; the belly is light glaucous-green as well as the prolegs ; the feet are the 

 same with brown booklets ; the true legs are shiny light greenish. L : 20mm ; 

 B : 8mm. 



Pupa. — {v. marginal figure). — The chrysalis is of the Terias type with wings 

 yentrally prominently bulged out in a curve along their suture- 

 line, the thorax humped, the head produced into a "beak" in 

 front, the abdomen circular in transverse section from end of 

 wings, thinning in segments 10 to end. Here the ventral 

 bulge of the wing-suture line is not very accentuated, the 

 apex of the curve being situated at about § its total length 

 from front end of pupa to the front margin of segment 9, 

 where it ends ; the beak is conical, equilateral, its base being 

 reckoned as the whole pupal diameter at front margin of seg- 

 ment 2 ; the real beak is only the very extremity of this cone 

 and it is very short ; segment 2 is about half the length of this 

 cone, has its surface parallel to the pupal longitudinal axis, 

 its front margin dorsally curved concavely and gently back- 

 wards, the hinder margin curved gently forwards towards it \ 

 the thorax is twice the length of segment 2, only gently 

 "humped," has its surface (taken as the plane subtending the 

 hump-curve) parallel to pupal axis and its hinder margin a. 

 gentle curve meeting the wings in a shallow, sharp angle 

 considerably less than 90° ; the lateral outline is nearly absolutely parallel 

 from shoulders to segment 8, these lines converge gently from shoulders 

 to eyes, then meet in the beak ; the wings are thus only slightly expanded 

 laterally ; the cremaster is nearly square, gently concave at end, depressed 

 dorsally between little-prominent, subdorsal ridges, slightly depressed 

 ventr'ally between the rounded marginal ridges, each hardly-prominent 

 extensor-ridge ending in a little point or sharp tooth anteriorly ; the 

 suspensory booklets are arranged in a dense mass all along the posterior 

 margin. Spiracle of segment 2 a mere linear indication, the others white, 

 oval, of usual size, flush. Surface of pupa finely aciculate-corrugated all 

 over, somewhat punctate on abdomen. Colour green with the lateral outline 

 along wings yellow ; there is always a black spot on the discocellulars and 

 the black spots at end of veins of hind wing show through indistinctly. L : 

 16 mm ; B : 3'5 mm. Depth at apex of wing-curve : 4 mm. 



Habits. — The eggs are laid on the iipperside of the leaf, from 50 

 to 60 in a batch, each egg separate and without apparent order. 

 The larv£e are gregarious throughout their existence, eat voraciously 

 and grow extremely rapidly. Eggs obtained on the 25th July 

 1903; larvse emerged next day ; changed to pupge on the 2nd of 

 next month at night ('some next night) and the imago emerged on 

 the 6th August 1903. The caterpillars feed in rows along the edge 

 of a leaf, lying closely pressed one against the other and continue 

 this up to the last stage when they become more independent but 

 still keep together in batches. The pupation takes place in the 

 ordinary way, each larva going off by itself beforehand ; so that the 



