52 ACIDALIA. By L. B. Protjt. 



in all the species which I can examine, is furnished with a pair of curved, diverging, moderately strong 

 spines, a marked contrast to the 6 nearly equal, very fine and threadlike, hooked-tipped bristles of that of 

 Ptychopoda. 



The genus is an extremely extensive and extremely natural one, being found wherever the subfamily 

 is represented, with the exception apparently of Chili, and showing exceedingly little structural variation, the 

 chief differences being in the nature of the antennal ciliation and m the formation of the ^ hindleg; the 

 latter may be moderately long and comparatively slender, though even then extremely rarely provided with 

 spurs and never with the middle spurs, or the tibia may be very much thickened, and in the latter case the 

 tarsus may vary from nearly normal length to almost complete abortion. Even in colour and pattern the majo- 

 rity of the species show great uniformity and their discrimination is often a matter of no small difficulty. 



The genus has been known by a number of different names — Acidalia, Lepto7neris, Craspedia, 

 Emmiltis, Dosithea and others. There can be hardly any doubt that Sch rank's Scapula, which would be the 

 oldest name, was really founded upon ornata Scop, and ought never to have been used m any other sense ; but 

 as in the present case historical usage has overridden strict logic, I have not thought it necessary to displace 

 Acidalia, which is older than the various Hiibnerian names sometimes substituted for it. Moreover, the 

 ofwftto-group might possibly be constituted a separate geniis according to the shape of the wing and a few 

 other small characters, and if that view were taken the great residue would still stand as Acidalia. A few syste- 

 matists have separated the species with a pair of spurs present on the ^ liindtibia as a geniis {Pylarge 

 H.-Sch.). It is greatly to be wished that this were biologically tenable, as it is such a useful character; but it se- 

 parates off from the rest a few species of such different facies that we are forced to the conclusion that the 

 retention of the spurs m the evolutionary history of this genus has been casual only. Still, as it is so convenient 

 taxonomically, I have retained Pylarge in a subgeneric or sectional sense. For the rest I have retained as 

 nearly as possible the order of Staudinger's Catalog, which is in the hands of nearly every Palearctic Lepidop- 

 terist and which shows, on the whole, a very natural seqiience. It has, however, been necessary to remove a 

 few species of different structure {Glossotrophia) and to introduce oc/woZewcato H.-Sch., remotata Guen. and aequi- 

 fasciata Chr., which were entirely misplaced by Staudinger. 



A. Section Pylarge*). (J hindtibia with terminal spurs present. 



As already stated, this section is m a sense arbitrary, merely indicating the least specialized forms in 

 the genus. It embraces probably seven groups, if not more; teriiata. Schr., the type of Pylarge, being nearest 

 the pomt of origm of such normal species of Acidalia as the floslactata-groujt; ansula.ta Led. and its allies 

 more specialized in shape ; a small group with stronger palpus, typified by impersonataWalJc. ; the narrow- winged . 

 species which have hitherto been called Lycaxiges Bull. ; one or two species which are so similar in facies to 

 the marginepunctata-gvowp of Acidalia that they are evidently in almost the direct line of ancestry to them; 

 two or three exceedingly smooth-scaled, glossy species typified by gastonaria Obth. ; and a single, aberrant- 

 looking species, steganioides Btlr., with better developed antennal pectinations and short cell of the forewing, 

 which may prove to form a separate genus. Perhaps the simplest structural analysis reduces these groups to 

 four, and this latter arrangement is here adopted. 



impersonata-group. 



(J antenna Avith long, fasciculate ciliation; palpus stout and extending beyond frons; hindwing not 

 greatly narrowed, second subcostal sometimes stalked. 



cineraria. A. cineraria Leech (3 k). Pale cinereous, irrorated with brown, and marked with brown lines. Except 



that the postmedian and subterminal lines should be somewhat more sinuous, incurved between the radials 

 and the former here rather markedly dentate, our figure gives a very perfect idea of this neat little species. 

 Some specimens are more weakly marked, the lines indistinct and the dark shade distally to the postmedian 

 almost entirely absent, the discal spots are also occasionally reduced in size ; but the variation is never so great 

 as to render it difficult to recognize. On the underside the forewing is more brownish, the hindwing more 

 whitish, both wings very weakly marked, the postmedian line the most noticeable. From the following species 

 cineraria differs in the more arched costal margin of the forewing, rather larger size, less brownish ground- 

 colour and less straight postmedian and subterminal lines. Onlj^ known from Korea and Japan, occurring 

 in May and June. 



A. impersonata is a rather variable species in colour, and very variable in the strength of the markings, 

 and has received several names. I have so httle material available for study that I am unable to decide how 



*) See also subtilaia Chr., which should be transferred here. 



