23,4 Patton: The Genus Musca lAnnxus 311 



are the vectors. Several species are known to be suitable inver- 

 tebrate hosts of species of Habronema, and the evidence so far 

 seems to point to their being the transmitters of these helminths 

 to equines and bovines. They should always be taken into 

 consideration when investigating an outbreak of any parasitic 

 disease among animals, and are therefore of importance in veter- 

 inary medicine. 



GROUP III 



This group consists of the true biting-blood-sucking species 

 which are only found on animals and in their vicinity, and which 

 breed exclusively in cow dung. Although there is no experimen- 

 tal or other evidence to show that any of the species of this 

 group are associated in the transmission of disease-causing 

 organisms to animals, as blood-sucking flies they must be looked 

 on with suspicion. 



I will now deal with the species according to the groups to 

 which they belong and in the above order. 



SPECIES OP GROUP I 

 Musca vicina Macquart. 



Musca flavinervis Thomson. 



Musca atrifrons Bigot. 



Musca flavifacies Bigot. 



Musca flavipennis Bigot. 



? Musca biseta Hough. 



? Musca divaricata Awati. 



Musca determinata Patton (nee Walker). 

 The collection contains 5 males and 3 females from Manila 

 (McGregor) and 2 males and 8 females from Alabang, Rizal 

 Province, Luzon (Mitzmain) . The specimens, with the exception 

 of one female, agree with Macquart' s types of Musca vicina, and 

 are the species referred to by me in a recent paper as Musca 

 domestica (atypical), in which the male has a very much nar- 

 rower front than the typical domestica L. In that paper I ex- 

 pressed the opinion that the following were probably also this 

 species : 



Musca sanctae-helenae Macquart, Saint Helena. 



Musca lateralis Macquart, Mauritius. 



Musca basilaris Macquart, Brazil and Mexico. 



Musca frontalis Macquart, Chili. 



Musca analis Macquart, Chili. 



Musca consanguinea Rondani, Mexico. 



Musca senegalensis Macquart, Senegal. 



Musca flavinervis Thomson, Ross's Island. 



