— 27 — 



An Introduction to a Classification of the North American 



Lepidoptera. 



By John B. Smith. 



(Continued from p. 8i, vol. I.) 



Somewhat allied to the Sesiidce in appearance and in habits are the 

 ThyrididiZ, few in number both as to genera and species. Like the Se- 

 siidce the imagoes are diurnal in habit. The larvae are little known. The 

 European species lives on Cleinatis in cone shaped cases and gives out 

 an unpleasant Hemiptera like odor. It is short, stout, cylindric, with 

 small tubercles and single hairs and has i6 feet. 



The imagoes are small and stout with strong long tongue, large pro- 

 jecting and bristly palpi, and spindle formed antennae, the basal joint 

 considerably enlarged. In the male they are singly pectinated. The 

 ocelli are wanting, eyes naked, distinct, though not prominent. The 

 legs are stout, clothed with long stiff hair, the middle tibia with one pair, 

 posterior with two pairs of spurs. Thorax robust, smoothly clothed. 

 Abdomen smooth, with a long slender anal tuft. The median cell is 

 simple, the primaries twelve veined, all the veins separate, dorsal or in- 

 ternal vein furcate at base. The secondaries have two internal veins, costal 

 vein free from base — altogether 8 veins. 



We have two genera — Thyris agrees with the 

 family characters. Platythyris is unknown to me in 

 nature, but according to Grote and Robinson's 

 description it contradicts nearly every family cha- 

 racter, and leaves only the superficial habitus to 

 authorize its reference here. According to them 

 the antennae are rather long, slender, filiform and 

 naked. Head sunken, unprominent ; palpi as in 

 Thyris. Eyes globose, small, vertex narrow. Pro- 

 thorax square, wide and short, not projected in front Venation of Thyris. 

 of the wings as in Thyris, closely scaled. Abdomen stout, sessile, not 

 exceeding secondaries. Wings white ; prmiarries more than half as wide 

 as long, apices obtusely rounded, external margin entire, slightly sinuate, 

 being outwardly rounded before internal angle ; antennal margin straight, 

 equalling the costal margin in length. Secondaries wide and full nearly 

 as large as the primaries, external margin very sinuate. Legs as in Thyris. 

 The venation is not described and therefore its reference here may per- 

 haps prove proper — if so, the definition of the family must be enlarged. 

 I shall not be unprepared however to find that it does not belong to this 

 familv at all. 



