I UK rUIBES OF I'lERINAK. 1039 



Mimicry in this yroup is tVoqueiit ami often almost complete. "The 

 genus Leptalis," writes Bates (Joiirii. cut., 1M()1), "was supposed, both 

 by Boisduval and Doiibloday, to have a real atHnity with the Ilcliconidae, 

 as the species not only resemble that family in shape, markings and colours, 

 but they also have, as Doubleday states, a structural similarity to species 

 of Ithomia (a Heliconideous geiuis) in tlie niiiration of tiic winiis. The 

 two groups furnish a most curious instance of deceptive analogical resem- 

 blance. There is, in truth, the widest possil)le difference between the two 

 in all essential characters of affinity — a fact which a careful study of the 

 legs in the Hhopalocera will satisfactorily prove. . . . The species [of Lep- 

 talis] in the Amazon region are also extremely rare ; they inhabit the 

 shades of the forest, and mimic the different species of the dominant 

 group Heliconinae, in whose company they are always found, thus sug- 

 gesting the idea that it is only by means of this close, adaptive resem- 

 blance that they escape total extinction." 



Several fossils belonging to this subfamily have been found in the tcr- 

 tiaries of Croatia and southern France, and a single one in the beds of a 

 similar age in Colorado. 



Table of tribes of Pierinae, based on the egg. 



Egg distiiK-tly fu^siforln. roiiiulcil at each end, the baseat most scarcely more than half as broad 



as the nikiille ; vertical ribs very slightly elevated, delicate, generally numerous 



Rhodoceridl. 

 Egg obscurely fusiform, the base tapering but little, truncate, generally three-quarters the 

 width of the middle; vertical ribs distinct, sliari) and moderately prominent, and compara- 

 tively few in number. 



Summit of egg distinctly rounded Anthocharidi. 



Summit of egg distinctly truncate Pieridl. 



Table of tribes, based on the caterpillar at birth. 



Uppermost serially ranged appendages of body approximated in laterodorsal rows. 



Dermal appendages conspicuously longer at the extremities of the body than in the 



middle Rhodoceridl. 



Dermal appendages of nearly uniform length throughout the body Pleridi. 



Uppermost serially ranged appendages of body widely separated in rows not higher than a 

 supralatcral line Anthocharidi. 



Table of tribes, based on the mature caterpillar. 



Either all the hair supporting papillae of the body are of equal or subequal size, or the larger 

 ones are numerous and arranged in transverse and not longitudinal series; longitudinal 

 markings comparatively rare; body tapering forwardiii front, the front pair of legs notic:e- 



ably smaller than the succeeding Rhodoceridi. 



The hair supporting papillae are of unequal size, the larger generally conspicuous, moderate 



in number and arranged in longitudinal and (excepting on the thoracic segments) not in 



transverse series; longitudinal markings conqiaratively common; body scarcely tapering 



forward in front, the front pair of legs only slightly smaller than the others. 



Whole body comparatively slender; head much broader than high; abdominal segments 



usually divided into seven sections Anthocharidi. 



Whole body comparately stout ; head scarcely ornot at all broader than high; abdominal 

 segments divided into six sections Pieridl. 



