540 Mr. G. A. K. Marshall 071 



raised in the air. This j)osition is probably to prevent the 

 male running along the side, for copulation is effected 

 from the side. It might however be done in order to 

 allow the male to see by her abdomen that she was gravid, 

 for I have a case in my note-book (P. ijigea) in which the 

 male ran up and felt the abdomen with his palpi and then 

 flew off. In the Acraeas however I have observed several 

 cases of copulation taking place in A. iKtrma and A. horta, 

 and in all of them the male seized the female on the wing, 

 grasping her with his intermediate legs about the thorax 

 or base of the fore-wings, and they would fall struggling to 

 the ground, where coition woukl take place. If this is 

 the normal method of copulation, and unfortunately my 

 observations have been too few to enable me to feel sure 

 of it, then any organ which would protect the female from 

 the attentions of an unlimited number of males would not 

 only be useful but absolutely necessary. 



Malvern, July 15, 1897. — The other day I saw a pair 

 of Acr.'ca enccdon struggling together on the ground, the 

 male ckasping the female round the thorax from below. 

 Unluckily a second or two after I noticed them they 

 separated, so that I had not time to see whether it was 

 really the sac which prevented coition. However I caught 

 the female and found she had the sac fully developed and 

 hard. 



C. A Ehodesian Muscid Fly Parndtic on Man. 



[Mr. E. E. Austen informs me that the fly sent by 

 Mr. Marshall belongs to the Mnscidiv, and is certainly a 

 near ally of the genus Bengalia. A closely similar or 

 possibly identical species with precisely similar habits 

 occurs on the West Coast of Africa. Mr. Austen's observ- 

 ations upon this latter entirely confirm Mr. Marshall's 

 conclusions as to the method by which the larva enters 

 the skin, Mr. Austen proposes to publish a full description 

 of the species — E. B. P.] 



Salisbury, A^^ril 19, 1901. — I should be glad to know 

 the name of the parasitic fly I send. It has been a great 

 scourge this year in Salisbury, especially among young 

 babies, the maggots forming a painful boil-like swelling 

 under the skin. One baby had no less than sixty maggots 

 extracted from it, and there have been several cases in 

 which they have had a dozen or more. 



