244 MR. H. vr. BATES ON BUTTERFLIES FROM PANAMA. [JunC 23, 



Hind wing, above, reddish tawny, semitransparent, with a well- 

 defined black outer border, broad near the apex, and gradually nar- 

 rowing to the anal angle. Beneath, the same, except that there is a 

 submarginal row of large silvery-white spots. Body brown ; wing- 

 lappets reddish tawny. Antennae black ; club yellowish. Expanse 

 2" 2'". 



This species is of the same size and shape as Bircenna epidero of 

 the Amazons region ; it has, however, no near relationship to that or 

 any other of the variable forms of this genus. 



13. Ithomia victorina, Guerin. 



Heliconia victorina, Guerin, Iconogr. Regne Animal, texte, p. 470. 



Ithomia victorina, Hewitson, Exot. Butt. Ith. fig. 75. 



This species is hitherto known only as inhabiting Venezuela and 

 Bolivia ; it is entirely absent from the intervening plains of the Ama- 

 zons, where no form at all nearly related to it is found. There is 

 one example in the present collection. 



14. Ithomia nephele. Bates. 



Ithomia nephele. Bates, Trans. Linn. Soc. vol. xxiii. p. 548. 



This interesting form appears to be abundant on the isthmus, 

 there being twelve examples in the collection. It is very closely 

 allied to I. nero (Hewitson, Exot. Butt. Ithom. f. 37), differing only 

 in being smaller and in the lower discocellular nervule of the hind 

 wings lying at a much more acute angle with the median nervure. 

 It is found also at Tabatinga, on the upper part of the Amazons re- 

 gion (being quite absent from the lower part thence to the Atlantic); 

 its line of migration, therefore, like that of /. victorina, would seem 

 to lie along the eastern side of the Andes, the easternmost chain of 

 which it has crossed to reach the Isthmus of Panama. 



15. Ithomia iphianassa, Doubleday. 



Ithomia iphianassa, Dbldy.in Dbldy. & Hewits. Gen. Diurn. Lepid. 

 pi. 18. f. 3; Hewits. Exot.'Butt. Ith. f. 91-93. 



Local var. or race panamensis. 



Ithomia iphianassa has been recorded as inhabiting Venezuela and 

 New Granada, in which latter region it appears to be very unstable. 

 It has lately been received also in some numbers from Canelos, on 

 the eastern slope of the Andes in Equador (sent bj' Spruce, the well- 

 known botanical traveller), but, if we may judge from the large 

 number of examples sent, all closely resembling each other, exists 

 there as a well-marked and constant local variety or race. The single 

 specimen contained in the present collection from Panama appears 

 to represent another equally well-marked race. Thus I. iphianassa 

 would seem to be one of those interesting forms whose present con- 

 dition throws great light on the formation of species, being very 

 variable towards the centre of its area of distribution, and showing 

 the segregation of distinct races or semispecies in different parts of 

 the confines of its area. It is to be remarked that whilst the Canelos 



