414 



ll ivprci^eiils Ww European J. he/u/iiria, Imt is iiiiich niorr dnisriy 

 speckled. 



Larva. — I have raised it at Brunswiek, iMe , lioni Hie Missouri eurranl. 

 Accordiiijj; to my recolleetioiis. i1 is a larjie thick woim, with a few small lidx^r- 

 eles, the heail notched, the l)ody of the same thickness througiiout, and dark 

 brown. The pnjia is l)rown. ol' tiie usual siiape, and is subterranean. 



JIISTON Leach. 



"Bisloii Leach, Kdin. Eiic.vl-1., ix, IM, ISl.'-i." 



Liicid Hiibn. (iu part), Vciz., :U9, ISIS. 



Amijhidaxis Treits. (in part), Scbiu. Knr., vi (.), 2129, 1B27. 



Dup. (ill part ), Lep. Frauci^ vii (iv), 268, If-Sit. 

 JUstoii Stt'pli. (ill part), Noinciifl. Br. In."., 43, 1S29. 

 AiiqMdasia Boisd., Geu. Biil., 195, 1S40. 



H.-ScU., Schm. Eiir., iii, 99, 1S47. 

 r.istoti .Stepb. (iu part). Cat. Br. Lep., 163, 18.50. 



Lederer (in part). Verb. Bot. ZdoI. Gcs. Wieu, 177, 18.J3. 



Giien.,Pbal.,i, 204, 18.57. 



W.allc, List Le|). Met. Br. Slus., xxi. 303, 18C0. 



The species of Biston are distinguished from those of Aynphidasis by 

 the smaller, more sunken head, the more hairy spherical thorax, and tiie 

 rather smaller, shorter abdomen. The fore wings have the costa straigl.it, not 

 curved toward the apex, vvliich is subrectangular, while the outer edge is nuudi 

 less oblique, and is a good deal shorter than the inner edge of the wing The* 

 hind wings are a little larger proportionally than in Amphidasis. In ct)lora- 

 tion, the species of Biston differ from those of Ampliidasis in the three dark 

 lines on the fore wings being subparallel, the outer one not being bent. 



Lnrva. — "Caterpillars cylindrical, smooth, without other eminences than 

 the trapezoidal ones which form two snuiU isolated points on the 11th ring; 

 head globular; living on trees. Chrysalides quite short, subterranean." — 

 Guenee. 



IksTON URSAEiA Walker. Plate 11, fig. 7. 



Bi«U»i iirnaria "WaXk., Can. Nat. and Gi'id., v, 201, 180(1 ; Li,st Lep. Ilet. Br. Mils., xxi. 3U5, 1800. 



2 c? and 1 9. — Body and wings dark granite-gray. AntenujB black, in the 

 male heavily pectinated. Palpi blackish. Body concolorous with the wings ; 

 the thorax is a little darker than the. abdomen, with two transverse dark lines 

 and a V-shaped line behind. Fore wings uniformly dark granite-gray, darker 

 and more densely speckled than in B. hirtarius of Europe, with three trans- 

 verse, obscure, dusky lines, as in /tirff/ritt.s, represented by l)lack spots on the 



