no. i. BOMBYCINE MOTHS OF NORTH AMERICA— PACKARD. 175 



CALIGULA SIMLA (Westwood). 



Plates XLI, fig. 1; XCVIII, fig. 3. 



CALIGULA [AUSTROCALIGULA] HELENA (White). 



Plate XL, fig. 5. 



GRAELLSIA Grote. 



Satumia Graeixs, Annales Soc. Ent. France, PI. 8, 1850. 



Attacus Rambur, Cat. Syst. Lep. Andalousie, p. 378, 1858. 



Saturnia Milliere, Annale Soc. Linneenne Lyon. (Nouv. SeV.), XVIII, p. 1, 1872. 



Actios Maassen and Weymer, Beitr. Schmett., Ill, figs. 40, 41, 1873. 



Tropaea Kirby, Syn. Cat. Lep. Het., I, p. 765, 1892. 



Graellsia Grote, Die Saturniiden, Mitth. a. d. Roemer Museum, VI, p. 26 (no descr.), 1836. 



Imago. — <? , <? ■ Head moderately wide between the eyes, the front being covered by long 

 irregular hair-like scales; <s antenna? very broad, pectinated to the tip, the joints unusually 

 long; those of 9 primitive in structure, the distal pectinations less than one-half as long as 

 the proximal ones, the branches ending in a few scattered setae toward the end and at tip. 

 Palpi small, not visible, being concealed by the hairs of the front; they are depressed, and are 

 more vestigial than in Actias. 



Fore wings equilaterally triangular, not falcate, the outer edge a little longer than the 

 inner, and only between one-fourth and one-fifth shorter than the costal edge. Hind wings in 

 S with a short narrow pointed tail, less than one-half as long as the entire wing and also shorter 

 than the wing is wide; in 5 the tail forms only a broad angle or projection turned outward, 

 and less than half as long as tail of <? . The wings are thin, the squamation being comparatively 

 sparse. 



Venation: In fore wing vein II t and II 2 wanting. (For other details see PL XLIII, figs. 

 3, 4.) The discal cell short, spur of vein VI t being the vestige of vein VHj is longer than in any 

 of the group Actianae or any Saturniid known to us. 



Hind wings; S vein III 3 and IV X arise very near together, in Actias they are far apart at 

 their origin; the discal cell is short, the discal veins being situated at or only just beyond the 

 middle of the wing. 



Markings: Discal spots or ocelli all four alike and extending to the veins on each side of the 

 discal area; they are round, those of the fore wings free, not connected by a band with the costal 

 band; the distal veins pass through the middle, and on the outer side is a crescentic irregular 

 clear space, the outer edge not being well defined. The rings of the ocellus are not continuous 

 except the outer black one, the others are discontinuous; the middle semicircle blue inside, 

 and represented on the outside of the discal veins by a much broader yellow semicircle. Three 

 submarginal dark brown bands on the fore wings, two on the hind wings ; no definite intradiscal 

 lines. The costal band is lilac reddish, and the veins are widened in appearance by red scales, 

 producing a very unusual effect. The wings are thin, not densely scaled, and of a delicate 

 pea-green, but with more reddish brown than in the other genera. The body is clothed with 

 loose wooly hairs, those on the thorax with scattered tufts of ochreous hairs. Abdomen reddish- 

 brown, banded with pale ochreous fawn. 



That the imago is a primitive ancestral form is strongly indicated by the very long vestige 

 of vein VII (and part of the lack of veins Hj and II 2 ), by the short tails, especially those of 

 the $ , the free ocelli of the fore wing, and especially by the Samia-like reddish body and the 

 whitish ochreous bands of the abdomen, as well as the loose irregular squamation. 



The great disparity in shape and markings between the sexes only affects the hind wings 

 with their tails and the antennas. 



Larva. — In its generic characters the larva differs remarkably from those of the other 

 genera of the group. The shape of the body is very primitive, mucli as in the Noctudiae and in 

 Perisomena caecigena, the body tapering toward each end, and being round and cylindrical. 

 It is not ornamented with tubercles bearing spines, but the tubercles are low, flattened, button- 



