270 MEMOIRS NATIONAL ACADEMY OF SCIENCES. vol. xii, 



Oxytenis (0. lamis); the basal joint short, the second very long and large, thick, extending very 

 far (for this family) beyond the front; third joint small, depressed, not so distinct as hi 0. lamis. 

 Eyes moderately large. 



Fore wings of almost exactly the shape of those of Platypteryx, the apex being much more 

 produced than in Oxytenis, and square at .the tip; the costa is much curved toward the apex; 

 outer edge deeply excavated toward the apex; inner angle rectangular. 



Venation: Very different from that of Oxytenis since II [III, in revised nomenclature] is 

 very short, arising not within the origin of the discal vein but far out near end of I [II]. II, 

 wanting. In both wings the forward discal vein is much curved inward, the hinder vein oblique 

 and not curved. Hind wings full, apex not so round as in Oxytenis, more angular; outer edge 

 regularly convex and rounded; inner edge nearly straight and long; the end of the abdomen 

 reaches a little beyond the middle of the hind wings. Venation remarkable for the presence of 

 a long vestige of vein VIII. 



The type of this genus is Attacus honesta Stoll. Druce's Oxytenis malacena from Panama 

 is a member of this genus, the species of which range from Nicaragua to the Amazons. 



EUSYSSAURA HONESTA (Stoll). 



Plate XXXVI, fig. 3. 



Attacus honesta Stoll, Pap. Exot., IV, t. 302, C. D. (1781?). 

 Oxytenis honesta Walker, Cat. Lep. Ilet. Br. Mua., V, p. 1182, 2, 1855. 

 Oxytenis honesta Kirby, Syn. Cat. Lep. Het., p. 770, 1892. 

 [Dr. Packard adds in pencil, ? malacena Druce.] 



One <? . Body and wings uniformly ochreous brown, the color of a dead leaf. Wings 

 strikingly similar in shape, color, and markings to Platypteryx. Fore wings with no distinct 

 basal line. A minute black discal dot with a few white scales on the inside or in front, forming 

 a very faint thin broken indistinct line, ending in a white dot on vein II. About halfway 

 between the discal dot and the outer edge of the wing is a reddish brown line beginning on the 

 middle of the inner edge, and ending on the apex of the wing, which is dark brown, frosted 

 over with fine white scales. An irregular zigzag line begins beyond the extradiscal,, but nearer 

 to it on the inner edge of the wing than to the inner angle ; it then approaches the extradiscal 

 line, and runs nearly parallel with it to the apex. Beyond the extradiscal line of both pairs 

 of wings, the wing is darker than within. 



Hind wings with the extradiscal line passing close to the discal spot. Beyond it is a zigzag 

 line; the space between it and the extradiscal filled in with darker brown than on the rest of 

 the whig. 



Beneath decidedly ochreous, except on the outer half of the hind wings, i. e., the region 

 beyond the extradiscal line. 



Expanse of fore wings, 62 mm. 



Length of fore wing, 3 1 mm. 



Breadth across the discal [spot], 15 mm, 



Length of liind wing, 22 mm. 



Breadth of hind wing, 18 mm. 

 This moth strikingly recalls Platypteryx, though much larger, and like that moth it is prob- 

 ably protected from observation by appearing like a piece of sere and brown leaf. Were it not 

 for the difference in size, the zealous advocates of natural selection as invoked to explain such 

 resemblances might regard this as brought about by selection. But as in many other cases so 

 considered, the striking similarity in shape and markings were more probably brought about 

 by similar environmental causes, without reference to the biological milieu. 

 Geographical distribution. — Nicaragua to Amazons. 



