SATURNIA PAVONIA. 331 



pavonia, except that it is longer, narrower, and has not so pronounced 

 a neck as the latter. It is composed of very hard and tough silk, 

 which cuts like thin horn. The outer surface is rough, covered 

 with a thin coating of stout, wiry silk threads. The interior has a 

 smooth glazed surface, two separate coats of the viscous silk having 

 apparently been used in its construction. This can be best seen 

 by opening the cocoon lengthwise. The opening, like that of S. 

 pavonia, is constructed on a similar principle to that of a crab- or 

 lobster-pot, with the exception that it prevents ingress and not 

 egress. In the cocoon of S. pyri this trap is double, a distance of 

 about T ^- of an inch separating the outer from the inner. The cocoon 

 of S. pavonia also has remnants of an outer trap, but it is imperfect, 

 being little more than an open ng with ragged edges, while the 

 inner is even more perfect than that of S. pyri (Bacot). 



Pupa. — The general colour blackish \ the whole surface is finely 

 wrinkled, and nowhere presents any spines, or points, or any pits ; 

 the ventral organs (legs, antennae, etc.) and abdominal segmental 

 incisions red-brown. The head narrower than the thorax, which 

 again is less wide than the front abdominal segments, which in- 

 crease in size from the ist to 4th, and then decrease to the cremaster. 

 The labrum and clypeus prominent ; inter-antennal region pale in 

 colour as if thin and delicate; the maxillae short and enclosed 

 between the first pair of legs, the ist and 2nd pairs of 

 legs extending beyond the antennae, which are fixed frontally ; 

 the second pair of legs extending about four -fifths from the 

 base towards the apex of the wings. The glazed eye is very in- 

 conspicuous. The prothorax, placed frontally, is ill-developed ; the 

 mesothorax prominent ; the metathorax ill-developed ; a fine, smooth 

 line running down the centre of the thorax. The forewings with 

 a thick costal margin ; the hindwings showing from the metathorax 

 as a slight extension beyond the margin of the forewings to the 

 middle of hind margin ; the prothoracic spiracle in the suture 

 separating the pro- and mesothorax. The abdominal segments 

 show, dorsally, scars denoting the position of the larval tubercles. 

 The spiracles are placed laterally, and are conspicuous on the ab- 

 dominal segments 2 — 7, aborted on the 8th. Each consists of a 

 narrow red-brown slit set in a prominent black rim. The ventral 

 area is flattened and shining. The movable incisions are placed 

 between 4 — 5, 5 — 6, and 6 — 7. The cremaster flattened out and 

 bearing about 24 long black hairs graduating into shorter ones. 

 The genital organs are clearly seen on the 8th and 9th abdominal 

 segments in the $ , and on the 9th in the S as usual (Tutt). The 

 antenna-cases are nearly as well developed in the $ as in the $ 

 pupa, whilst in the imagines the antennae are only very slightly 

 pectinated in the $ , and only occupy a small portion of the 

 space covered by the pupal ones (Bacot). 



Comparison of pup^e of Saturnia pyri and S. pavonia. — The 

 pupa of S. pyri has a low double cremaster with a few short scythe- 

 shaped spines on it, in which feature it resembles the pupa of S. 

 pavonia, except that, in the latter, the ventral hollow and cremaster 

 are developed to a far greater extent. It, however, differs greatly 

 in shape from the pupa of -5. pavonia, which is much flattened out 

 laterally, curved ventrally, and tapers rapidly towards the head and 



