328 



irreater sliiftiiiir :ni(l viirialioii of stniclural cliaractcrs than in (liis, and yet it 

 is nearly alwny.s easy (o rcrognize an Acidalia. 



I retain Treilsclike's name l"or tlie gronp, as Hiibner's Arrhostia only con- 

 tained five out of over one liundred European species, and his views of" the 

 irenus were vauue (■oiu|)are(l with Treitschke's. Prol)ubly fifty or sixty addi- 

 tional species are to l)e discovered n\\ this contincMit. But it is to be hoped 

 that isolated descriptions of tlicni will not l)e published. 



Hi/nop.s)s of the Species. 



ATLANTIC STATES. 



A. Species small ; foi-(,' wings elongated ; hind wings rounded: 



a. Ash-gray; fore whiijn mthfnur lines btyoitd ihe discal dot : j 



Fore wiugs with outer edge convex (. ossulata. ' 



Fore wings with outer edge very straight ; apes jiointed A. pairrorata. K 



l). intUc, irilh oclircous lines: ^ 



Small; wiugs uarrow ; much eloogated A. longipennata. .^ 



Like longipcnnaia, hat whigs hvondeT A. peralbaia. 



Like peralbaia, but larger ; suhniargiual line often zigzag, and black or 



oehreons ,(. piinclojimbriata. 



c. J'ore icUuis long; hind iiings rounded: 



Larger tluui any of the jirecediug ; silky-ochreous, with slightly darker 



lines J. 2>roduciata. 



B. Costa of fore wings very straight, paler than rest of wing; hind wings 



short ; outer edge less convex than nsual : 



Hind wings very short, less convex thau usual, triangular; pale greenish, with 



numerous line obscure lines I. insnlsaria. 



Reddish tinged with vermilion; costa reddish, and connected with three red- 

 dish transverse lines A. pannaria. 



Like pannaria, but hind wings as in insulsaria ; costa of fore wiugs conspicu- 

 ously white ,,(. albocostaliaUi. 



C. Of large size; hind wings iisiuilly angled; hind tarsi short: 



W^hitish; no well-marked lines; fore and hind wings much rounded A. roliindopennata. 



Perfectly white; very large; hind wings much bent I. nivosata. 



Hind wings slightly bent, fawu-gray, with four distinct, slightly darker lines.. J. inductata. 

 Like induetata, but brick-red, and more hairy, with dark reddish-brown lines.. -J. sentinaia. 

 \Vhitish-ochr(!ous; hind wings distinctly bent; two ochreous lines common to 



both wings; suuiller than enudeata .(. iinadrilineata. 



Small. Wings narrow; hind wings very angular ./. eaaiminata. 



Fore wings sublaleat(i ; whitish-ochreous ; hind wings much bent ; both wings 



with heavy black lines and patches on the outer third A. cnudeala. 



Wings subfalcate, nearly while, with two very distinct ochreous lines, common 



to both wings j, ordinata. 



PACIFIC STATES. 

 A. Diminutive; hind wings rounded : 



Like 0S8H;<t(«, gruuite-gray j. granitaln. 



■ I 



