4 ME. r. WALKER ON THE DIPTEEA 



the warmer parts of the earth ; and several species of them inhabit 

 these isles. Asilus and Leptogaster are generally distributed, and 

 the former contains a vast number of species : of the few here 

 mentioned, all are new, excepting A. longistylus and A. Barium ; 

 and the geographical range of the latter extends to Ceylon. In 

 Aru there is one species of the Asiatic genus Bamalis. 



The Bomhyliclce, so various in form, are very scarce in these 

 isles, and appear only in four genera — Therma, AntTirax, Geron, 

 and Systropus ; the last is a widely spread genus, but contains 

 very few species. In this family the archipelago especially differs 

 from Australia, and has no representatives of the peculiar forms 

 and of the large number of species that inhabit the latter region. 



The LeptidcB comprise a few species belonging to Leptis, Chry- 

 sopila, and Suragina, of which genera the last one is new, and 

 contains two species from Gilolo. 



In the Dolichopidse there are many species belonging to Psi- 

 lopus, BolicTiopus, Diaphorus, and Ohrysohis ; and as all the species 

 of this family are of small size, it is probable that they are much 

 more numerous. 



Loncliopterid<s. — It is doubtful whether the new genus Cadrena 

 belongs to this family. 



The PlatypezidcB and the Pipunculidcs are each limited to one 

 species. Fipunculus has been found in Amboyna ; it also occurs 

 in Australia. 



SyrpJddce. — Some genera of this family are selected for notice. 

 Ceratophya was diitcovered by Dr. Doleschall ; it was before only 

 known in North America. The species of Ceria are very few ; yet 

 five of them are contained in this list, and four of these are new. The 

 species described as G. lateralis is C. indica. The genus Eristalis 

 contains four of the few Dipterous species whose geographical range 

 extends beyond the archipelago. E. AmpMcrates inhabits Hin- 

 dostan and China ; J5J. Andrcsmon and E. ceneus inhabit Hindo- 

 stan ; and E. arvorum inhabits China. BaccJia Ampliithoe and 

 Ascia hrachystoma are also natives of Hindostan ; so also are 

 SyrpTius cegrotus and S. alternans ; and >S^. ericetorum inhabits 

 Africa. 



Oonopidce. — One species of Conops was discovered by Dr. Dole- 

 schall ; it has little affinity to the Australian representatives of 

 the genus. 



Muscidce. — Several of the subfamilies of this most extensive 

 group are very slightly represented in the list ; but it is probable 

 that a large number of new species will be discovered. 



