220 Bulletin American Museum of Natural History [Vol. XLIII 



wings, though some females, identically marked, are greatly hypertro- 

 phied. The insects are myrmecophilous, and perhaps some peculiarity 

 in their mode of nutrition in the larval state, the relative ease or diffi- 

 culty with which they secure their sustenance in this stage of their 

 existence, may account for the very abnormal difference in the size of 

 individuals. Until some observer carefully works out their life-history 

 by breeding we shall not have a solution of the problem with which the 

 present writer feels himself confronted. 



(338) 1. Megalopalpus zymna (West wood) 



Miletus zymna Westwood, 1852, in Doubleday and Hewitson, Gen. Diurn. Lep., II, 



p. 503, PI. Lxxvi, fig. 7. 

 (? M. simplex Rober, M. bicoloraria Capronnier, M. similis Kirby, M. metaleucus 



Karsch, M. zymna Smith and Kirby.) 



The collection contains three specimens, all females, taken at Medje, 

 no two of Avhich are exactly alike, though each of which can be matched 

 in an}^ large collection such as that in the possession of the writer. They 

 are as follows. 



a. 9 . Dwarfed, expanse 24 mm., markings of the under side as 

 in M. simplex, but almost obsolete and so pale as onty to be detected 

 by close scrutiny. Like a score of specimens before the writer from Lolo- 

 dorf, Cameroon. Taken at Medje, June 27, 1910. 



b. 9 . Expanse 43 mm. Combining on under side characteristics 

 of M. simplex, as defined by Aurivillius and shown in Rober's photo- 

 graph, and characteristics of M. zymna, as depicted by Smith and Kirby 

 = M. metaleucus Karsch, fide Aurivilhus. On the upper side of the 

 secondaries dark border reduced to a mere trace. Taken at Medje, 

 September 27, 1910. Can be matched by numerous specimens in collec- 

 tion of writer, some with black hind borders on upper side of hind wings, 

 some without such borders, some fight on the under side, some dark, 

 some fulvous, some slaty gray, as in Smith and Kirl^y's figure ('Afr. 

 Lycsenidte,' Plate xii, figs. 1, 2). 



c. 9 . Smaller than the preceding specimen. Expanse, 33 mm., 

 with the hind margins of the secondaries much l^roader and darker than in 

 that specimen, but the markings of the under side much paler, though 

 closely resembling those of specimen b. Taken at ^ledje, August 1910. 



Lachnocnema Tiimen 

 This is another myrmecophilous genus which stands in much need 

 of intelligent revision. The writer has a mass of material at his com- 

 mand, collected in tropical East Africa and in tropical West Africa, as 



