( 426 ) 



viiriegateil witli grey than in others ; yellow area of hindwing rather constant, 

 always reaching to bas(! ; the yellow ])atch at anal angle is ratlier large in some 

 individnals, vestigial in others. Tlie black snbniarginal line of the forewing, above, 

 distinct in lunca, is barely vestigial at aju-x and in middle; a greyisli, curved, 

 snbtriangnlar shade extends from costal margin to end of 11^, bordering a halfmoon- 

 sliaped darker distal marginal space. The underside is generally uniform in colour, 

 with the snbniarginal line of tiie forewing distinct at least from tip of wing to R", 

 bordered grey distally. Distal margin of forewing more sharply angnlated at R^ in 

 some specimens, such individnals having generally also a small tooth at R-. 



cj. Sexual armature as in grisea, dilfering from that of pallida in the much 

 smaller i)atch of spines on the inner surface of the clasper above tlie harpc, and in 

 the much shorter whip of the penis-sheath. 



?. Vaginal plate (PI. XLI. f. 5) also as in grisea, more triangular than in 

 pallida ; vaginal orifice subapical, transverse, covered by a broad flap ; proximal 

 jiart of j>late almost regularly folded. 



llah. Guatemala to Bolivia and Rio de Janeiro. 



In the Tring Mnseum 5G specimens from : Guatemala ; Chiriqni ; Paramba, 

 Ecuador, 3500 ft. iv. '97, dry season (Rosenberg) ; Chanchamayo, Peru ; St. 

 Domingo, S.E. Peru (Ockenden) ; Mapiri R., Bolivia, viii. ix. (Stuart) ; Rio de 

 Janeiro. 



Sfi:!. Perigonia lusca. 



Sphinx liixca Fabricius, d'l'ii. Ins. p. liTJ (1777) (Am. merid.) ; Goeze, £«/. Jki/lr. iii. 2. p. 'JOli. 



n. 22 (1780) ; Fabr., Sj,,,: Jus. ii. p. 140. d. 5 (1781) (Am. merid. insulis !) ; id. J/,(«/. /hs. ii. 



p. 92. n. ,'j (n«'?) ; timel., Si/st. Xcf. i. 5. p. 2372. n. 51 (1790) ; Fabr., Enl. Si/st. iii. 1. p. 3M. 



n. 6 (179.^). 

 Perigonia hixca, Walker, List Lep. Ins. D. M. viii. p. 101. n. 1 (1856) (partim) ; Clem., Pruc. A<: 



Nat. Sc. Philad. iv. p. 138. n. 15 (1859) (synon. partim ; Mexico; S. Am. ; W. Indies) ; 



Morris, Cat. Lip. N. Am. p. 17 (1800) (partim) ; Clem., in Morris, Syn. Lep. N. Am. p. IGl). 



n. I (1862) (partim) ; Grote & Rob., Froc. Ent. Hoc. Philad. v. p. 152. n. 23 (1865) ; Boisd,, 



Co)is. Lip. Giiafem. p. 67 (1870) ; id.. Spec. Gen. Lep. EH. i. p. 325. n. 9 (187.'i) ; Butl., Tram. 



Znul. Sue. Loud. ix. p. 532. n. 5 (1877;; Druce, Biol. Centr. Am., Lep. Net. i. p. 3. n. 1 (1881) ; 



Kirby, Cat. Lep. /let. i. p. 636. n. 6 (1892) ; Druce, I.e. Sujipl. p. 299 (1896) (Mexico ; Gu.ite- 



mala ; Chiriqui). 

 *Perigonia restituta Walker, I.e. xxxi. p. 32 (1864) (Mexico ;— Mus. Brit.). 



There is apparently no constant ditfereuce by which the various forms here 

 united to one species can be distinguished ; we have vainly endeavoured to find 

 constant distinguishing characters. The sexual armature, apart from individual 

 variation, is the same in all of them ; but that is not an argument of weight in the 

 present genus, as s})ecies so dift'erent in colour as sttdta and grisea agree also in 

 tliese organs. The details of the shape and colour of the wings which have served 

 the various authors as specific characters are unreliable, there occurring so many 

 intermediate specimens that it is impossible to say where one so-called species ends 

 and another begins. The difficulty of dealing with these insects is increased by tlie 

 lack of sufficient material from the West Indies. A larger series of individuals 

 from the islands may possibly prove that lefebruei and jamaicensis are also not 

 specifically distinct. 



c? ? . Yellow band of hindwing not extended to base, seldom as broad as the 

 blackish distal border of the wing, often reduced, not rarely obliterated. Black 

 submarginal line of forewing curving from apex to hinder angle always distinct ; 

 a conspicuous, mostly straight, brown antemedian line crossing M distally of M-, 



