Lepidoptera of New York and 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 x in Citheronia ; M l and M., 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 seta?, but with the primary setas 

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

 or more pairs of thoracic spines each bearing two primaries; seta? 

 ia and ib, iia and iib 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 Hemileucinas are poisonous (like nettle), and have 

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

 the poison. . 



Pupas 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 Lacosomidas) 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- 



