8 SOUTH-AFRICAI^ BUTTERFLIES. 



of moderate length, slender, clothed with scales ; tibige slightly, tarsi 

 very bristly ; terminal spurs of middle and hind tibire very small. 



Abdomen very slender, elongate, arched, laterally compressed. 



This is a very well-marked genus, containing a few closely-allied 

 species, and having a very wide range over the tropical and sub-tropical 

 regions of the Old World, from Western Africa to North- Western 

 Australia. Its extreme sleuderness of structure, long abdomen, and 

 contour of wings give it a strong resemblance to the Palaearctic genus 

 Leucoijhasia — which it also resembles in its plain white livery, some- 

 times blackish-tipped in the fore-wings — but it is widely different in 

 neuration, having only two instead of five subcostal nervules in the 

 fore-wings, and very large instead of extremely small discoidal cells. 

 On the whole, Pontia appears to be most nearly related to the small 

 Australian genus Elodina, Felder, which presents very similar neura- 

 tion as well as colouring, but has the apex of the fore- wings pointed, 

 and the first subcostal nervule of the hind-wings originating near the 

 extremity of the discoidal cell. Next to Modina, the genus Terias 

 comes nearest to Pontia. 



In habits the Pontia: greatly resemble the European LcucophasicB. 

 They frequent wooded places and flit feebly about bushes and herbage, 

 preferring shade to sunshine. 



Besides P. Alccsta (Cram.), which is the only s^^ecies known to 

 occur in South Africa, the Ethiopian Region yields P. Medusa (Oram.),^ 

 a larger form from the Gold Coast with greenish under-side markings, 

 and two from Madagascar— one of which (P. sylvicola, Boisd.) is 

 exceedingly close to Alcesta, while the other (of a singularly pure 

 white) appears to be undescribed. 



239. (1.) Pontia Alcesta, (Cramer). 



Painlio Alcesta, Cram., Pap. Exot., iv. pi. ccclxxix. f. a (17S2). 



Painlio Narica, Fab., Ent. Syst., iii. i, p. 187, n. 578 (1793). 



Pontia Narica, Boisd., Sp. Gen. Lep., i. p. 432, 11. 3 (1836); App. Voy. 



Deleg. Afr. Aust., p. 586 (1847). 

 Pontia Alcesta, ^^^ii\\avn., K. Sv. Vet.-Akad. Hand]., 1857; Lep. Rhop. 



Cafifr., p. 6. 

 Pontia Alcesta, Trim., Rhop. Afr. Aust., i. p. 26, u. 12 (1862). 

 5j M Hopff., Peters' Raise Mossamb., Ins., p. 349. 



Plate X. fig. i ($). 



Exp. al, I in. 5-9 lin. 



Pure-white ; forc-ioing until a Uackish apical border and a blackish 

 discal sp)ot. Fore-wing : costal margin irregularly hatched and speckled 

 with blackish to about middle, and sometimes very sparsely speckled 

 beyond middle ; apical border moderately wide at apex, but attenuated 

 to a point at its commencement on costa at extremity of first sub- 

 costal nervure, and similarly at its hind-marginal termination (which 



^ PajJ. ExoL, ii. pi. cl. fig. F (1779). 



