Life-history of 'Di\sy\\e\ea ohscuvn, Winnertz. 587 



The piipre of this species (see Rieth, pp. 424-425 and figs. 

 60 & 65) are 3 to 4 mm. long ; the prothoracic horns are 

 ribbon-like and throughout their length show a spiral 

 structui-e. The post-abdominal forked protrusions are short 

 and simple. 



Finally, it can be added that several species of Dasyhelea 

 have been reared by Carter, Ingram^ and Macfie (1920) in 

 the Gold Coast, Africa, from the rot-holes in various trees, 

 " such as the flamboyant, the silk cotton, the mango, a 



species of Cijnoiaetra, etc from partly decomposed 



roots or bases of banana stumps, and from the rotted wood 

 at the sides and ends of canoes " (p. 202). The larvae and 

 pnpje observed by these authors still await description, but 

 from the account of their behaviour it follows that they are 

 very similar to those of Dasyhelea obscura. 



VI. Predaceous Dipterous Larv^ living upon the 

 LarVjE and Pup^ of Dasyhelea obscura. 



The larvae and pupae of D. obscura are destroyed in 

 great numbers by the tliree following species of carnivorous 

 l)ipterous larvae : — 



1. Phaonia cincta, Zett. (Anthoniyidae, see Keilin, 1917, 



pp. 362-375). 



2. Systenus adpropinquans, Loew (Dolichopodidae). 



3. Systenus scholtzii, Loew (Dolichopodidae). 



VII. Parasites of Dasyhelea Larv.e. 



The following is the list of the parasites which I have 

 found in the larvae of D. obscura : — 



Funyi. 



1. Monosporella unicuspiduta, Keilin, 1920.— A parasitic 

 yeast invading the whole body-cavity of the larvae and des- 

 troying them before they succeed in pupating. The parasite 

 is characterized by having the asci with only one acicular 

 spore. There is only one other species of this genus : 

 M. bicuspidata, Metchnikoif, discovered by Metchuikofif 

 (1884) in Daphnia magna. 



Sporozoa. 



2. AUantocystis dasyhelei, Keilin, 1920. — An intestinal 

 gregarine M'ith elongated sausage-shaped cysts, living in the 

 mid-gut of the larva between the peritrophic membrane and 

 intestinal epithelium. This gregarine does not seem fatal to 

 its host. 



