478 R. OSTEN SACKEN 



Thus we have seven species (or six if longividens and lati- 

 videns be considered as one) all from New Guinea and the 

 surrounding islands. This geographical distribution of the group 

 makes it almost certain that the original Achias oculatus Fab. 

 never had Java for its patria, but came from N. Guinea, or still 

 more probably, from the Aru Islands, whence, for centuries 

 past, birds of paradise have been exported. If A. oculatus really 

 occurs in Java, it is difficult to explain why it has never been 

 brought to Europe since? Once being granted that A. oculaius 

 comes from the same region as the six species enumerated 

 above, it becomes exceedingly probable that it is synonymous 

 with one of them. As far as the data go, which we possess 

 about A. oculatus (brown costal border and altogether yellow 

 femora), A. ampUvidens from the Aru Islands comes nearest to 

 it. Only the specimens of ampUvidens in the Brit. Mus. have a 

 much narrower head than that of A. oculatus, as shown in the 

 figure. 



k few words about the systematic position of Achias. I be- 

 lieve it to be an Orlalid , related to Lamprogaster , which also 

 have very large tegulae (like a number of other Platystomina). 

 The Ortalidae contain several genera with a laterally very de- 

 veloped head ; but it does not follow that these broad-headed 

 genera all belong in the same group. Wiedemann went too far 

 when he formed a family Aclnidae for Aciiias , Plagiocephalus 

 and Zi/gothrica^ because they are all broad-headed. Plagioce- 

 phalus , as Loew suspects ( Mon. N. Am. Dipt. Ill, 26) 

 may belong to the liichardina , a group in which Gerstaecker 

 described two very broad-headed Richardiae (Stett. Ent. Zeit. 

 1860). Zygothricttj, to all appearances, is no Ortalid at all; a 

 specimen which I saw in Vienna Museum made on me the im- 

 pression of a Drosophila ; and I found since a passage of Loew's, 

 who reached the same conclusion (Monogr. N. Am. Dipt. Ill, 

 24) ; a passage which I had lost sight of since I translated that 

 volume. 



