NORTH AMKRICAN LEPIDOrTERA. 215 



Belonging to this subfamily is the genus Ardoiiotus, which yet 

 offers characters so peculiar that Mr. Grote placed it in tlie Caudi- 

 berbes with Pogocolon and At'Uopos, while Mr. Butler questions its 

 right to belong to the Sphingida^ at all. The species is so extremely 

 rare that I have been able to examine only a single specimen, and I 

 hold to my previously expressed opinion* that it belongs here rather 

 than elsewhere. As, however, I have not been able to make the same 

 careful examination as in the other forms I place it at the end of the 

 series ; in fact it must either end or head it, for it belongs nowhere 

 else. It cannot remain where Mr. Grote i)uts it on account of its 

 antennal structure as well as its other characters — in fact the only 

 reason I can imagine for its position among the Macroglosdnoe, is the 

 small size and plump form which somewhat resembles that of the 

 species with which it is associated. 



TRIFTOtJOSJ Brem. 

 Bull, de I'Acad. Imp. St. Petersb. 1861, iii. 



Head sunken, small, with a small median crest. Palpi very short, 

 terminal joint minute. Tongue minute, membraneous ; vestiture 

 fine silky hair. Antennte fusiform, without a terminal hook ; simple 

 in the 9 » biciliate in the % . The ciliations are ranged in two series 

 on each side of the middle of each joint, and approach at tip, form- 

 ing thus an api)roacli to the double bi-pectinations of Oressonia. 

 Thorax plump, heavy, not tufted, the vestiture very dense, fine and 

 silky hair. Abdomen plump, cylindric, obtusely terminated, uni- 

 formly covered with fine spinules which are concealed by the vesti- 

 ture, which is somewhat flattened. Legs strong, short, subequal in 

 length, the anterior shortest ; in all the tarsi much exceed the tibiae 

 in length. Middle and hind tibiae with a single ])air of short termi- 

 nal spurs, anterior with a stout curved spine at inner side of tip — 

 not spinose. Tai'si finely spinose. Primaries large, with regularly 

 scalloped outer margin and 12 veins; 10 very short, from 9 to the 

 costa. Secondaries large, anal angle somewhat produced, outer mar- 

 gin slightly and irregularly sinuate; 8 veins, costal straight, or but 

 little sinuate ; 6 and 7 from the end of the subcostal ; 3, 4 and 5 at 

 equal distances from the end of the cell ; o from the cross vein, much 

 nearer to 4 than to 6. 



The genital structure of the male is characteristic. The supra- 

 anal plate is thick, bent into a broad flat hook. The inferior spur is 



* Erit. Am. i, 86. 



