LEPIDOPTERA OF NEW YORK AXD NEIGHBORING STATES 661 



angle, supported by a more or less distinct humeral vein; Sc and R 

 widely divergent almost from base, connected close to base by a 

 rudiment of R! in Cit heron ia ; M t and M 2 connected with R-stem by a 

 full-strength longitudinal vein, the cell weakly closed or open below 

 M 2 ; 1st A lost. 2d A normal; 3d A very short and rudimentary in the 

 typical Saturniids. which have the inner margin more or less con- 

 cave toward the body, and not folded. 



Egg of flat type, usually thick-shelled, ovoid, without definite sculp- 

 ture, but often with characteristic markings. Larva in first stage with 

 branching spines bearing several setae, but with the primary seta? 

 distinct ; or. for the major part, with primary setae only, but with one 

 or more pairs of thoracic spines each bearing two primaries; setae 

 ia and ib, iia and lib of thorax on single tubercles, i and ii of abdomen 

 separate, iv and v of abdomen on a single bifurcated tubercle. Later 

 stages with abundant but usually fine and inconspicuous secondary 

 hair on body, but little or none on head, warts all several-haired, and 

 usually modified into branching spines (fig. 418) or knoblike struc- 

 tures (fig. 417) often with the hairs themselves rudimentary. The 

 spines or knobs often unequal, and some of them often rudimentary. 

 Warts iii and iv+v usually forming spines; but i of the ninth segment 

 of the abdomen single-haired and soon lost in the general mass of 

 secondary hairs. Seta ii similarly lost except on the ninth and some- 

 times eighth segment; i of the eighth segment, or ii of the ninth, or 

 both, usually (in our species always) fused with their mates on the mid- 

 dorsal line, those of the eighth forming the so-called "caudal horn." 

 The spines of the Hemileucinae are poisonous (like nettle), and have 

 the setae modified into conical caps which easily break off, setting free 

 the poison. 



Pupae moderately to heavily chitinized. always obtect. but capable 

 of considerable progression in the Citheroniida?. Head without trans- 

 verse sutures ; mouth on ventral surface of body ; tongue never reaching 

 tip of wings, and normally only about a fifth as long as wings; labial 

 palpi wholly concealed ; no maxillary palpi ; fore femora exposed ; fore 

 and middle legs usually meeting on the middle line behind the tongue, 

 and the wings meeting on the middle line behind them; antennas very 

 broad, usually more than a fifth as broad as long, larger in the male, 

 where they may almost completely cover the other structures. Abdo- 

 minal segments sometimes spined but never (as in the Lacosomidae) with 

 an anterior and no posterior row of spines. Pupa clothed with micro- 

 scopic secondary hair. 



I here recognize two families. Besides these there is a third family 

 in South America, characterized by fully scaled antennae, and appar- 



