92 BRITISH LEPIDOPTERA. 



Sexual dimorphism. — The antennae differ as in other Sphinges, 

 the 2 being without the long pocket-forming hairs. In addition 

 the 2 antenna is shorter (9*5mm.-io'8mm.) than in the $ , it is very 

 distinctly more slender *34mm. to '40mm,, and appears to De more 

 clubbed, the $ antenna reaching its greatest thickness from 

 about the 30th to 40th joints,, thence declining at first very 

 slightly, the 2 antenna does not reach its greatest thickness till 

 it reaches the 40th joint, and maintains it till it reaches the 45th, 

 thence declining more rapidly than does that of the g . In both sexes 

 the terminal bent point involves 8 to 10 segments. The minute 

 terminal joint of the palpi seems rather better developed in the $ , 

 and its included cavity more obvious. It is possible to believe 

 that the scaling of the antenna is in three definite rows, but they 

 are so irregular that an unbiassed description would rather note 

 them as without very definite arrangement. The anterior tibial 

 spurs differ a little in the two sexes, but very little, those of the 

 $ being about i^omm. long, of the 2 i'33mm. The 2 is more 

 robust, and, as in Eiimorpha elfienor, the tapering to the" apical point 

 of the abdomen is confined in the 2 to fewer terminal segments 

 than in the $ (Chapman). 



Variation. — There is considerable variation in the amount of 

 yellow and rosy tints, as well as in the intensity of the lines, 

 observable in this species. The thorax and abdomen sometimes 

 entirely rosy, sometimes almost entirely olive-ochreous with only a 

 slender rosy collar and median area to thorax, and rosy sides to 

 abdomen. As a race the Perthshire examples are very striking, 

 the ground-colour very distinctly olive-ochreous, the transverse line 

 well-developed, the costal patches pinky-crimson, the patch between 

 the second and fourth transverse lines often continued to the inner- 

 margin. The hindwings somewhat suffused, at the apex the outer- 

 marginal area also somewhat suffused = var. scotica, n. var. The western 

 Irish specimens have a markedly yellower ground-colour, the 1st, 

 2nd and 4th lines developed, but the 3rd nearly obsolete, the normal 

 red patches on the costa and outermargin often more or less 

 obsoletely marked with pinky-grey, giving the wings an unicolorous 

 appearance, the discoidal lunule fairly distinct, the hindwings also 

 more uniform, the basal area not very dark, and the outermargin 

 only faintly red = var. hiberm'ca, n. var. The South Wales specimens 

 rather incline to the Irish type. The British examples from Notting- 

 ham approach the well-marked Scotch type, but have the red of a 

 much deeper crimson tone, whilst the Kent and Sussex examples 

 often have the transverse markings almost obsolete, the crimson-red, 

 however, being well marked. In our collection the following appear 

 to be the chief forms : 



(1). Anterior wings, ground-colour clear yellow-ochreous, transverse lines almost 

 obsolete, red areas of a bright rose. Posterior wings with dark basal area well developed, 

 marginal area faintly red with dark shading, central fascia same tint as ground- 

 colour ol fnrewini^— /><;/<<////.<•, Linn. [Linne's typical description appears to refer 

 to this form. " Purpureum " is possibly only a general term lor purple-red or red.] 



(2). Anterior wings, ground -colour olive-ochreous, transverse lines ill- 

 developed, red parts bright crimson ; the three areas of the posterior wings equally 

 clearly separated=ab. clara, n. ah. 



(3). Anterior wings, ground-colour olive-ochreous, transverse lines well- 

 marked, red parts bright ciimson ; the central and red parts of hindwings some- 

 what dark-shadcdz=var. (et ab.) scotica, n. var. (et n. ah.). 



