MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 63 



The geuus, as shown by the hirval characters, is more o-otiorulized than Anisota, since the 

 spines on tlie prothoracic and abdominal .segments arc laro-ci-, anfl tlie sphingiform imagoes or 

 moths are rather more primitixe and ancestral. 



The species of the genus diti'er very con.sidcral)ly. and may l)c divided into s(>veral groups or 

 what may be perhaps regarded as incipient genera. The most sphingiform group of species and 

 tiiat nearest Syssphinx is the Brazilian ^1. sidxux/nlata. A. falla.r Hoisd., and A. hisecta, while the 

 rounder-winged species ^1. alholhieata^ A. ]ieili(jhi'0(]fii, and ^1. bfco/arnvG later, more degenerate, 

 or modilied forms. A. Mcolor, with pectinated 9 antenna^ shows a remarkable divergence fi'om 

 th(> normal 9 form, the front of the head ))eing wider, while the tongue is not visible. We 

 consider those species with a well-developed tongue as the more primitive forms. 



Druce states: ''■ Adelocephala 1 think will have to be divided, the typical species having 

 pectinated antenna' in both sexes, those of the A. alholineata group being only pectinated in the 

 males. 1 have not sutEcient material, however, to be certain how far this character holds good." 

 It appears, however, that only A. 1>!r<>lor has pectinated anteiuia' in the female. (See fig. 8.) 



The South American and our A. hisecfa are apparently the more primitive forms, both as 

 regards the sphingoid shape of the bodj' and wings and the nioi'e fully developed maxilhe. As 

 the type found its way into North America it seems to have undergone a reduction of the 

 maxilhv until they practically became aborted, while the outlines of the wings became less 

 distinctive and less specialized, as seen especially in A. hicolor, which in this respect approaches 

 Anisota. It is interesting to observe that all the South American species (except ^1. (mflioiuMn) 

 have sharp fore wings and subtriangular hind wings, while in several of the Central American 

 and North American species the wings tend to become broad and rounded at the apex. 



The most aberrant species is A. ((Jholineata. Its maxilhe are comparatively well dcvelopeil. 

 I have not been aide to examine the male antenme, having no examples of that se.x. It differs in 

 venation from all the other species in the much wider discal cell of both wings, and in vein III, 

 of the fore wings, which arising between the anterior discal vein and III3, springs off very near 

 the origin of the latter. The two discal veins taken together form a straight line, not being- 

 curved as in most of tlie otherspecies; the subcosto- radial (II) vein is nuich curved, so that the cell 

 between this and III is much wider than in any other species of the genus. If the genus is to 

 be subdivided ^i. alhol ineiita should be generically separated from all the other species, but it is 

 l)etter to wait until we know the larva and its history. 



Egg. — Flattened, oval-c3dindrical, disk-like, each end alike. Shell smooth under a low [)ow<'r, 

 but when highly niagnitied seen to be oi'namented with faint polygonal ai'cas, with a swollen 

 nucleus in the cent(>r. 



Litri'it. — Head subconical, narrowing above. l?ody cylindrical, inclined to be slightly com- 

 pressed; in the more primitivi; species all the segments, exci'pt the prothoracic, bearing long, 

 high, saber-shaped dorsal spines as long as the body is thick; tubercles // nearly atrophied: in 

 the more specialized species (.1. hicohn; etc.) the four thoracic and caudal horns much longer than 

 the abdoiuinal ones; of the latter those on each, or on the second, fourth, and sixth segments, 

 are stout, conical, smootii spines, conspicuously tinged with silver and rose red; no median spine 

 on the ninth abdonunal segment; suranal plat(> coarsely tulxM'eulated, but with no specializcMl 

 spines. 



}'<>"iig /<i/'rii, xtagi' I. — Ariued with four thoracic horns, three-fourths as long as the body, 

 and ending in bulbs bearing two dark rods; caudal hoiii spinulated. large, as long as the body 

 is thick, divided deeply into two setiferous lobes; tubercles // present on abdominal segments 

 1 to 9; suranal plate with three lateral and two terminal setifei'ous tubercles: the l)ody niai-ked 

 with conspicuous longitudinal stripes. 



PujHi. — Body moderatel}' stout, head rounded: Tuaxilke shoi-t. taken together farming a 

 nearly equilateral triangle; a group of three stout spines at base of and between, the antenme. 

 as in Anisota; surface of the integument more rugose than in .Vniscjta, and the spines a little 

 stouter; the cremaster is long, slender, narrow, rather deeply divided at the end, but not differ- 

 ing from that of Anisota. 



