96 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Pupa. — Much like that of Anisota and Adelocephala; the caudal spine being long and 

 slender and slightlj' forked at the end. 



Food plant . — It feeds on a high forest Mimosa. 

 Geographical range. — Nova Friburgo, near Rio de Janeiro. 



^^NISOTA Hlibner. 



(Plates XX.) 



^nisota HuEBNER, Verzeichniss Sehmett. p. 192. 1818-1822. « 



Dryocampa Harris, Cat. Ins. Mass. in Hitchcock's Report on the Geology of Mass. 4°, 1834, and 2(1 edit., 



p. 72 (p. 592), 1835; Treatise Inj. Insects, p. 293, 1841. 3d edit. 1862.— Walker, Cat. Lep. Het. Br. 



Mus. \l, p. 1495, 18.55. 

 Anisota Grote, Proc. Ent. Soc. Phil., Ill, p. 93. June, 1864. 

 Dryocampa and Anisota Packard, Proc. Ent. Soc. Phil., Ill, p. .384. Nov., 1864. 

 Adelocephala Boisduval (in part), Annales Soc. Ent. Belgique, XV, p. 88. 1872. 

 Anisota Dyah, List N. Amer. Lep., p. 75. 1902. 



Imago. — S and 9 . Head ju.st visible from above, not entirely concealed by the prothorax 

 as in Syssphinx. Front rather wide, not narrowing in front at the labrum, thus Vjecoming 

 triangular as in Adelocephala hlsecta and in Syssphinx; when denuded seems to be flat, somewhat 

 triangular {A. rubleunda, PI. XXXVI, tig. 3), or decidedly so in ^4. virghuensis (fig. 2); the 

 labral end of front i— i as wide as between the antenna^ while the surface is full and convex. 

 Antenna? of S bipectinated to a little beyond the middle; 15 pairs of pectinations, the basal pecti- 

 nations about as long as the proximal ones; the joints (12 in number) of the filiform end very 

 short, simple; the vestiges of the teeth very short and minute, and giving rise to thin tufts of 

 several fine setse. In 9 they are filiform and simple. Palpi scarcely visible, so short and feeble; 

 but denuded found to be 3-jointcd, joints 1-2 of nearly the same length, third joint about two- 

 thirds as long as second. Maxilla? either entirely wanting or minute, vestigial, not visible. I 

 can not discover in S ruhicunda and virginiensls any vestiges of them. 



Fore wings of S .short, narrow, subtriangular to triangular (especially in A. virginiensis); 

 costa curved toward the obtuse or subacute apex; outer edge nearly equal in length to the inner, 

 oblique, and either moderately full or straight. 



Hind wings short and broad, the outer edge convex, or (in A. virgijtlexsis) straight and 

 triangular, with the costa very convex toward the base. The wings reach to the last third or 

 fourth, or near the end of the abdomen. Legs moderately short; the fore tibial epiphysis 

 leaf-like, a little over half to two-thirds as long as tibia; no spurs. 



Venation (PI. XXXIX): as in Eacles, no vein 111^; IIIj originates about halfway between 

 the origin of anterior discal vein and that of IVj, /. e., beyond the discal cell, while in Cithe- 

 ronia and Eacles, III; arises inside of the origin of the discal vein (PI. LVIII, fig. 5, and p. 56). 

 A. dliisiiallls ditfers in vein 111 arising a little within the origin of the discal vein, as in 

 Eacles (PI. LVII, fig. 5) the di.scal veins together forming a regular curved line, those of the 

 hind wings oblique. Other less important difierences in the venation are brought out by the 

 figures of the diflerent species on Plate XXXIX. 



Coloration: The United States forms ocherous, bathed with lilac, or in the Mexican A. dis- 

 shiu'lk with ])urplish brown fore wings, and blackish hind wings; fore wings with a distinct discal 

 white spot, which is obsolete on the under side. 



Genitalia (PI. XLI): Compared with those of Adelocephala to which they are in some respects 

 (suranal plate) nearest allied, the sui'anal plate is much broader, and ends in two thick rounded 

 lobe-like processes; the chitinous end incurved; tip bidentatc; the claspers not so wide as in 

 Syssphinx, but much shorter and stouter than in Adelocephala, and nearer those of Sj'ssphinx, 

 tip ending in two unequal projections. The harpes (h) are often well developed, as in Citheronia 



" Scudder has shown that by the ond of 1822 only the first twenty signatures of Hubner's Verzeichniss were 

 printed, the first two signatures only having been printed in 1816, the date on the title-page. Proc. Am. Acad. Arts 

 and Sci., X, 1875, p. 96. 



