378 Lcjpidopterological Contributions. 



dora) ; Ilyperchiria, Iltibner, (varia, and otlicr Mexican 

 species) ; and Dirphia, Hiihier, (tarqninins). From this latter 

 genus several species from tropical America and Mexico, re- 

 ferred here by Mr. Walker, remain to be separated, as we are 

 satisfied from the study of material kindly communicated by 

 Mr. W. IT. Edwards. We place this tribe at the head of the 

 sub-family. In this position it forms a natural transition from 

 the Attach (the typical Bombycidae) to the Dryocamjnni / and 

 the genera present a series of distinguishing structural features 

 compared with either of those groups. Thus, while the $? an- 

 tennae are, as a rule, less heavily pectinated among the Attaci, 

 than these organs in the $ , we have them still less so, serrate, 

 or nearly simple in the Iiemileucini, and becoming demi-pec- 

 tinate or simple in the Dryocampini. Again, the S antennae 

 are gradually reduced in the Iiemileucini, and become 

 demi-pectinate in the Dryocampini. The lower genera of 

 the present tribe have the external margin of the primaries 

 straight, and the apices acute ; thus simulated by Eacles, with 

 which genus we would inaugurate the succeeding tribe. In 

 the Attaci, and in these two lower tribes of Ceratocampidae, 

 the larval forms are well defined and distinct. There is also a 

 separate habit of pupation and design of the pupal envelop- 

 ment. Thus, while the Attaci weave large and dense cocoons, 

 attached to objects free from and elevated above the earth's 

 surface, the Hemileucini spin cocoons of slight texture on or 

 near the ground, and granules of earthy matter or debris of 

 vegetation are apt to be mixed with the web. Again, the 

 Dryocampini enter the earth and form a subterranean cell, in 

 which the naked pupa reposes, showing an analogy of habit 

 with the Sphingidae — a totally distinct family. The falcated 

 Attacid primary becomes blunted in the Hemileucini, and 

 shorter, losing its typical shape and relative size and pro- 

 portion. Our Attacid genera : Telea, Hubner, (polyphemus) ; 

 Tropaea, Hiibner, (luna) ; Samia, Ilubner, (cynthia — introduced 

 from Asia) ; Callosamia, Packard, (promethea, angulifera) ; 



