No, 4. — 1848.] SKETCHES IN NATURAL HISTORY. 55 



the perfect fly is generally effected in from fifteen to 

 thirty days. 



P. Raliphron, var. This is a distinct species from the 

 true Haliphron which is found in Celebes. The larva feeds 

 on the Aristolochia Indica (Linn.), sassanda of^the natives. 

 The perfect insect is common and widely distributed, except 

 iu the peninsula of Jaffna, where, according to the Reverend 

 F. Taylor, it is not found. I do not remember seeing it 

 myself during either of the two visits I have made there at 

 different seasons of the year, 



P. Polymnestor. A common and widely distributed insect, 

 though rare in Jaffna. The larvae feed on different kinds of 

 Citrus, the perfect fly appearing plentifully in May. 



P. Epius. Agreeing in all respects with the last, except 

 that the dingy variety is rather scarce. 



P. Helenus. Not uncommon in the interior, at an eleva- 

 tion of about 3,540 feet. Larva unknown. 



P. Polydorus. Very common and widely spread ; larva 

 feeds on Aristolochia Indica (Linn.). Fly abundant in May 

 and June. 



P. Pammon. As the last, with the exception of the larva, 

 which feeds on Citrus. 



P. Hector. Common in July and widely distributed, 

 larva closely resembles that of Polydorus, and often found 

 feeding in company with it. 



P. Mutius. Not common ; larva feeds on Citrus. The 

 perfect fly appears in September. 



P. Polytes, Uncommon ; I have only captured about a 

 dozen specimens, and those in the month of June. It does 

 not appear to extend to the hills. The larva is unknown 

 to me. 



P. Crino (Fabricius). This splendid insect is very periodical 

 in its appearance, May being the season in which it is found 

 in any abundance. It is then common, flying swiftly, and 



