(■ 117 ■) 



present, or reelnced in tlic nnmber and longtii of the l>ristles, or tlie liristles not 

 prolonged to a comb ; pnlvillus always absent, but the lobe of the ])aronychinni 

 nuiy be present or absent. 



The more generalised species with paronychium, mesotarsal comb, verj' long 

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

 From this group eremitus branched off by acquiring the short first protarsal segment, 

 tiie spiny midtibia and the specialised larva. Another branch {canadensis, etc.), 

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

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

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

 ])eculiar genital armature form a side-branch, culminates in forms without 

 paronychium and without midtarsal comb. 



In two of the species (i-ancouverensis and perelegans) remarkable dichromatism 

 obtains, thfere occurring specimens with a black and specimens with a grey thorax. 

 The diftereuce is said to be seasonal in vancoiicerensis (see below). 



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

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

 lobes to the })aronychium, the other being without them. This is the first instance 

 met with by us among Lepidoptera — apart ivom. geographical mccs — 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-spiuose midtibiae and long lobes to the paronychium form a natural group, 

 if we except lanceolata, bnt the remainder comprises species which are jiartly much 

 less related inter se than with species of the first group, and wonid reijuire further 

 sjilitting up, if the first grou]) were treated as generically distinct. 



Larvae of the ligustj-i-type, or specialised in pattern and sometimes in structure. 



Pupa with a free tongue-sheath of varying length, appressed to the breast. 



Hab. Nearctic, Neotropic, and Palaearctic Regions. 



Thirty species, of which only four are Palaearctic. 



Key to the species : 



.1. Midtibia not spinose; paronychium with lobes. Hindwing 

 with a black basal jjatch. F(n-ewing generally with 

 two distinct stigmata. 

 a. Mesothoracic tegulae with a black middle line besides 



the thin black dorsal border .... d. 



Mesothoracic tegulae without black middle line . /. 



6. Metanotum with a golden-yellow spot on eacli side . x. 



„ witiiout ,, „ „ „ ,, . c. 



c. Fringe of abdominal tergites witii a yellow double 



spot 1)2. II. justiciar. 



Fringe of abdominal tergites without yellow spots . d. 



d. Middle of abdominal tergites of a yellowish russet 



tint, forewing washed all over with russet. . '.Ki. //. m'rops. 

 Middle of abdominal tergites olive or grey, ground 



colour of forewing grey ..... e. 



e. Edge of prothoracical tegulae yellow dorsally . . dS. If. separatii.'i. 



„ „ „ not yellow dorsally J'. 



