( 117 ) 



present, or rcJneed in the nuiubei' and Icug'th of tlie bristles, or the bristles not 

 prolonged to a comb ; pnlvillns always absent, but the lobe of the jiaronychinm 

 may be present or absent. 



The more generalised species with paronychium, mesotarsal comb, very long 

 tongue, long first protarsal segment and not spiny midtibia, are lugens and allies. 

 From this group eremitus branched otF liy acquiring the short first protarsal segment, 

 the sjiiny midtibia and the specialised larva. Auother branch {cawidensis, etc.), 

 had its origin in some such form as jusficiae ; while lanceolata may be regarded as 

 the prototype of the more specialised chersis, fancouiierensis and allies. Tliis latter 

 series, of which sequoiae aud colonulns with their clubbed ? -antenna and the 

 peculiar genital armature form a side-branch, culminates in forms without 

 paronychium and without midtarsal comb. 



In two of the s])ecies {rancou(crehi<is and pi'rclryans) remarkal)!e dicjiromalism 

 obtains, there occurring specimens with a black and sjiecimens with a grey thorax. 

 The difference is said to be seasonal in vancoucerensis (see below). 



We were very much surprised to find that, in perelegcms, this difference in 

 colour is accompanied by a difference in structure, the one form possessing long 

 lobes to the paronychium, the other being without them. Tliis is the first instance 

 met with by us among Lepidoptera — apart hora. geographical races — where individual 

 resp. seasonal forms differ in structure as well as in colour. 



We should have liked to divide the rather unwieldy mass of species at least 

 into three genera. Our attempts, however, to do so were a failure. The species 

 with non-spinose midtibiae and long lobes to the paronjxhium form a natural group, 

 if we except lanceolata, but the remainder comprises species which are partly much 

 less related inter se than with species of the first group, aud would require further 

 gjilittiiig u]i, if the first group were treated as generically distinct. 



Jjarvae of the Ugustri-i)-\ie, or specialised in pattern aud sometimes in structure. 



I'upa with a free tongue-sheath of varying length, ajtpressed to the breast. 



Ilab. Nearctic, Neotroinc, and Palaearctic Regions. 



Tiiirty species, of which only four are Palaearctic. 



Key to the species : 



A. Midtibia not spinose; paronychium with lobes. Hindwiiig 

 with a black basal jjatch. Forevving generally with 

 two distinct stigmata. 

 a. Mesothoracic tegulae with a black middle line besides 



the thin black dorsal border .... Ii. 



Mesothorac-ic tegulae witliout black middle lino . /. 



Ii. Me(aiiotnm with a golden-yellow spot on each side . .r. 



„ witiiout „ „ „ „ „ . f. 



c. Fringe of abdominal tergites with a yellow duuble 



Hjiot il2. If. jiintiriai'. 



Fringe of abdominal tergites without yellow spots </. 



il. Middle of abdominal tergites of a yellowish russet 



tint, f(jrewing washed all over with russet. . '.»;?. //. trn'ropx. 

 Midille of ubdominal tergites olive or grey, ground 



colour of forcwiiig grey ..... <'. 



e. Edge (jf pi'othoracical tegulae yelhnv dorsally . . Us. //. .vpiiratii.s. 

 „ „ „ nut yellow diirsally /'. 



