. 36 RHYACIA. By W. Warren. 



aequicuspis. E. aequicuspis Stgr. (12 g). Exceedingly like multicuspis Ev., but paler grey, with less distinct 



markings; marginal lunules small and regular instead of large and irregular. From Korla, Thianschan Mts., 

 Turkestan and from Mongolia; dubiously distinct. 



pygmaea. E. pygmaea Hamps. (7k). Forewing dark fuscous, dusted with grey; a black streak below base of 



cell; claviform stigma small, black-edged; orbicular and reniform with dark centres ringed with white; 

 hindwing white with dark veins and termen. W; Turkestan. Quite a small species. 



21. Genus: Rbyacia Hbn. 



Distinguished from Euxoa by the smooth rounded frons. Type B. lucipeta Schiff. 



Section I: Antennae of <? bipectinated to apex or nearly so. 



graslini. R. graslini Ramb. (7 i). Forewing pale ochreous , the veins and a costal streak greyish white ; 



stigmata distinct; claviform dark, narrow at base, the pale inner line angled below it; orbicular small, 

 flattened, ochreous with centre dark; reniform dark grey with inner edge pale; the cell dark; hindwing 

 white. Restricted to the west coast of France, where the larva is said to feed on the grasses of the sand-dunes. 



messaouda. R. messaouda Oberth. (7i). Resembles graslini Ramb., yellower ochreous, the cell and submedian 



interspace suffused with olive brown; costa and veins pale; claviform stigma much longer; orbicular without 

 dark centre: outer and submarginal lines strongly dentate; hindwing white, with apex evenly rounded. 

 Algeria and Morocco. 



'6 V 



vestigialis. R. vestigialis Rott. (= valligera Ghnel.) (7i). Forewing greyish ochreous, with olive fuscous shading 



varied with whitish: stigmata large, outlined in black; claviform elongate, orbicular and reniform with 



fuscous centres in a pale ring; orbicular small, often conjoined to reniform; submarginal line preceded by 



black dentations; hindwing white, with brownish veins and margin; the ? always darker, with the hindwing 



sagittiferus. wholly brownish. — In the typical form the markings are distinct on a pale grey ground; — ab. sagittiferus 



clavis. Haw. differs only in having the ground dark fuscous; — ab. clavis Esp. is pale reddish ochreous; the 



signata. forms in which the markings are more or less obsolete differ similarly in coloration; — thus ab. signata 



trigonalis. Boisd. has a pale grey ground; — ab. trigonalis Esp. is a small fuscous form with the stigmata large and 



nigra, outer margin dark; — and ab. nigra Tuft (= var. B. Guen.) is blackish fuscous with the course of the 



lineolata. median vein pale; — in ab. lineolata Tutt the wedge-shaped markings, usually submarginal only, extend 



through to the outer margin. — The imago occurs in August in sandy districts throughout Europe and in 



W. Siberia. — Larva greyish or greenish; dorsal line pale, with a strong black edge; lateral lines pale 



with darker edges; feeds on grasses and low plants. 



subrosea. R. subrosea Stph. (= rhomboidea Stph. nee Esp.) (7 i). Forewing rufous grey, dusted with pale 



grey; stigmata large, pale grey; the cell rufous or red-brown; the claviform obsolete; hindwing greyish 

 ochreous, with diffusely darker border; fringe ochreous. T}'pical subrosea Stph. occurred formerly within 

 subcoerulea. a restricted area in the fens of Britain, but is now extinct. — The form subcoerulea Stgr. (7 k) which is 

 bluer grey, is found in Sweden, Prussia, Russia and in Amurland. — Larva reddish grey, with paler lines; 

 the spiracular line brighter yellow ; food plants Myrica Gale and Salix. 



velata. R. velata Stgr. (7k). Forewing purplish grey along the margins, suffused with purplish brown 



along middle of wing, the cell still darker; the two upper stigmata small and grey; claviform obsolete; 

 lines paler, not dentate; hindwing pale grey. Ussuri, Amurland. 



atpicola. R. alpicola Zett. (= iveni Hbn). Forewing grey shaded with fuscous, with only a slight reddish 



tint in the middle, the stigmata, which are large, and the lines, fairly distinct; hindwing fuscous with pale 

 hyperborea. fringe; the ? smaller than the d* ; — ab. hyperborea Zett. (7k) has the grey ground more varied with 

 aquilonaris. reddish and fuscous, the markings clearer; — in ab. aquilonaris Zett., grey clouded with brownish fuscous, 

 alpina. the markings are blurred; all these greyer forms are from Lapland; — ab. alpina Humphr. & Westw., is 

 coerulescens. buff grey varied with red, occurring in the North of Scotland and Ireland; — ab. coerulescens Tutt is the 

 rich red-brown form with lilac-grey markings and blackish wedge-shaped streaks, found in the Shetland 

 carnka. isles; — ab. carnica Hering (= glacialis H.-Sch.) is the rufous insect taken in the Garinthian Alps. The 

 species occurs also in Switzerland, on the mountains of Silesia and Hungary, in Russia and in Amurland. — 

 Larva brown-red; dorsum with dark striae forming a row of V-shaped marks; dorsal and subdorsal lines 

 ochreous, partially black-edged; spiracular pale and obscure; feeding on various low-growing mountain- 

 plants, such as Vaccinium, Arbutus, etc. 



coraxa. R. coraxa Bung. (= quadrangula Ev. nee Zett. , oblongula Stgr., quadriplaga Bart.) (7k). Fore- 



wing grey-brown; the cell brown; stigmata concolorous with wing, the claviform rarely plain; all the 

 markings indistinct ; marginal area rather darker ; hindwing paler grey-brown. A local species found in the 

 Ural Mts. Russia, in W. Turkestan and Mongolia. 



