98 A YEAR OF COSTA RICAN NATURAL HISTORY 



size or in shape of wings, as to furnish a very typical case of 

 mimicry. Messrs. Godman and Salvin in their volumes on 

 the butterflies in the Biologia Ce7itrali-Americana mention 

 four other species namely: Eresia mecha?i{tis, Eueides zorcaon, 

 Heliconius telchinia and the female of Dismorphia praxinoe, 

 as having colors and patterns very similar to the first three 

 mentioned. The last four also occur in the same localities 

 with the first three and although we did not meet them to- 

 gether some of our readers may make their acquaintance in 

 nature and wish some means of distinguishing them apart, 

 for It will be noted that not merely seven species but seven 

 genera are Involved In this case of resemblance. 



One of these genera, Dismorphia^ has the usual number 

 of functional legs of Insects, six, and each of the two claws 

 at the tip of each leg split lengthwise or toothed, features 

 which place it In the family Plerldae. The other six genera 

 have only four legs used for walking, the first pair being 

 unfitted for this action, and in consequence belong to the 

 family Nymphalidae. This is divided into several sub- 

 families, of which we are here concerned only with the Dan- 

 ainse {Lycorea), Ithomiinae (Mechanitis, Melincea), Heli- 

 coninae {Heliconius, Eueides) and Nymphalinae {Eresia). 

 Danalnae, Ithomilnse and Hellconinas have the central 

 basal area of the hind wings known as "the cell" enclosed 

 on all sides, while in many Nymphalinae, Including Eresia, 

 the cell Is open at its outer end. The Danalnae and the 

 Ithomllnae have the last (hindmost) vein of the front wing 

 apparently formed by two veins uniting near the wing-base; 

 in the Heliconinse on the other hand this same vein arises 

 singly. One distinction between Danalnae and Ithomlinae 

 has already been mentioned on page 79, the males of the 

 former having two retractible tufts of hairs at the hind end 

 of the abdomen, but not along the front edge of the hind 

 wings, while the males of the Ithomlinae lack the abdominal 



