44 DONALDSON BODINE. 



BB. Anteniife of male with distal ami proximal pairs of pectinations suhtM[ual. 



Calosatui'nia. 

 AA. Antennre of both sexes with two paii"s of iiectinations to a segment. 

 B. Proximal and distal pairs subetjual in male, distal pair shorter in the female. 

 C. Distal pair of female very short, without haire of tlie second type-Telea. 



CC. Distal pair of moderate lensrth with hairs of second type Tropsea. 



BB. Proximal and distal pairs suhequal in both sexes.* 

 C. Distal pair of pectinations of female shorter than, or only equal to, the 

 proximal on the proximal segments. 



D. Distal pair wanting in a few distal segments Callosamia. 



DD. Distal pair present, at least in rudiments, to the distal end- . .Samia. 



CC. Distal ])air of pectinations of female longer than the proximal on the 



imtximal segments Philosamia. 



There is a gradual progression in complexity of development from 

 Colomdia on the one hand, to Samia or Philosamia on tlie other. 

 The females of Coloradia, Automeris and Callosaturnin, have a sin- 

 gle pair of pectinations to a segment, while those of the other genera 

 have two pairs. The males of tlie first two geuera have the distal 

 pair shorter, while the other have the two pairs subequal. There is 

 also a gradual increase in both sexes from one end of the series to 

 the other in the number and position of the cones. In Samia there 

 is not only an abiuidauce on tlie shaft, but many are on the pecti- 

 nations of the distal portion of the clavola. There is some doubt 

 as to whether S-tmia or P/ii/o.'<amia should be considered tlie higlier 

 form. The male Samia is more highly developed tlian llie male 

 Philosamii ; bat on the other hand, the female Samia is less devel- 

 oped than the female Phllo^tmia. I believe that now Ssmii is the 

 higher form, and that it has outstripped Phihsamia in specialization 

 in comparatively recent times. If the females lag behind the males, 

 as seems most probable, the condition we find in the two genera 

 would indicate that the male Philosamia has been long enough fixed 

 to allow the female to approach it in specialization ; while in Samia 

 the male is even now progressing in complexity, and the female has 

 not had time to ajiproiich it in development. There are many indi- 

 cations in the anteunie of Samia which point to its recent or even 

 present progress. The pectinations are not well established in form 

 and position ; the cones are variable in position ; even the segmen- 

 tation is more or less indefinite in portions of the clavola. 



* The genus Satiimia belongs somewhere in this sectioii. It is represented in 

 the United State.? by a single rare species. R galbiua. and no specimen i.s at hand 

 for study. The descriptions of the insect are too indefinite on points relating to 

 the antenuie to he of any value. au,l it is necesi^ary. therefore, to omit this genus 

 from the table. 



