OP THE EASTEEN AKCHIPELAGO. 5 



The TacMnides amount to less tlian 60 species. This number 

 appears very small when it is considered that the European spe- 

 cies of these parasitic Muscidae are excessively numerous. They 

 are in exact contrast to the Muscides — where the species are com- 

 paratively few, but occur in immense swarms ; whereas in the 

 Tachinides the species appear to be interminable, but none of 

 them are in any abundance. In this the Tachinides resemble 

 some tribes of parasitic Hymenoptera, and, like them, may have 

 been diversified in character by the numerous kinds of insects on 

 which they are parasitic. Hamaxia and Zambesa are the only two 

 new genera. Megistogaster Imbrasus inhabits China as well as 

 Borneo. 



Dexides. — Butilia may be mentioned as indicating in some of 

 the isles an approach to the Australian fauna, this genus being 

 restricted to the archipelago and to Australia. It is the largest 

 in size, and the most brilliant in colour, of all the Muscidae. 

 Felder has named a genus of Rhopalocera after Dr. Doleschall ; and 

 as my genus Doleschallia is very closely allied to Torocca, I have 

 united these two genera, and have annulled the former name. 



SarcopJiagides. — Sarcophaga, the type of this tribe, is very widely 

 distributed, and the species have much mutual resemblance. 8. 

 rujicornis inhabits Hindostan and Malacca ; and all the other spe- 

 cies in this list are merely insular. 



Muscides. — Idia is limited to the warmer regions of the Old 

 "World, and of the species here mentioned some have a wider range 

 than the generality of these Diptera : thus, Idia australis is found 

 in Australia, I. xanthogaster in Hindostan, and I. testacea in the 

 Mauritius. Two of the species of Musca have been already de- 

 scribed, and inhabit also Hindostan ; the rest are new, and some of 

 them are indicated as new subgenera. Musca domestica is omitted 

 from the list. 



Antliomyides. — These may be passed over without notice, as it 

 is probable that only a very small part of them are yet discovered, 

 and that they have been neglected on account of their smaU size 

 and duU colour ; and the same remark will apply to the Helomy- 

 zides, the Sorhorides, the Lauxanides, the Ascinides, the Geomy- 

 zides, the Phytomyzides, and the Hydromyzides. In the Helomy- 

 zides, the occurrence of Ccelopa may be mentioned as that of a 

 genus which seems to be nearly peculiar to other regions. It 

 swarms on the northern shores of Europe ; but in the Channel 

 Isles it is scarce, and another genus replaces it on the sea-weed. 



The Celypliides are closely allied to the Lauxanides, and are 



