OF THE EASTERN ARCHIPELAGO. S 



characteristics of the family are not much developed, Ptilocera 

 appears to be peculiar to these isles and to South Africa ; and F. 

 qiiadridentoM is the only Dipterous insect that has been found 

 in almost all the islands here mentioned. Clitellaria, Oydogaster, 

 Stratiomys, Oxycera, Chrysomyia, and Sargns are widely distri- 

 buted. Of JEudmefa only one species is known ; and it occurs in 

 Hindostan, Singapore, Sumatra, and Java. PhyllopJiora was 

 founded on a West African species, and Singapore is its only 

 other locality. Sermetia, to which Ulassicyta may be united, is 

 especially a South American genus, and has not been discovered 

 in Africa, nor on the continent of Asia, 



Ji^ylophagidcB, — It is doubtful whether this family has been dis- 

 covered on the archipelago; for perhaps Rliypomorplia may not 

 belong to it. This is very different from all other genera, though 

 it has some resemblance to the North American genus MacMcerus. 



Tabanidcd. — One species of Pangonia, a genus that abounds in 

 Australia, has been discovered in the archipelago. Tabanus is 

 especially characteristic of continents, and the species appear to 

 have been multiplied since the continents were established by the 

 joining together of islands. About 600 species of this genus 

 have been recorded. Ghrysops and Hcsmatopota are nearly as wide- 

 spread as Tahanus ; and G. dispar is among the few of these insular 

 species that appear also on the continent of Asia. 



Asilidce. — The Dasypogonites are of rare occurrence ; they are 

 represented only by 13 species and by 4 genera (Mydas, Disco- 

 cephala, Dasypogon, and Dioctria),2i\\. of which are found in several 

 other regions. In the Laphrites, the numerous species of Laphria 

 here recorded are the most remarkable features in the Dipterous 

 fauna of these islands. By far the greater part of them are of the 

 metallic-coloured group, which has very few representatives in 

 other parts of the world. Most of the species are very closely 

 allied to each other, and some of them will probably be considered 

 mere varieties. Perhaps the connecting links will disappear 

 by degrees, and the remainder will then be recognized as isolated 

 or clearly defined species ; or, in botanic phrase, the segregate spe- 

 cies which compose the aggregate species will partially cease, and 

 the true species will continue or will be more evident. It is well 

 known that some regions of the earth represent now the earlier 

 state of other regions ; and in like manner the preparatory esta- 

 blishment of species may be observed in some districts, while there 

 are no traces of such a process in other districts. Among the 

 Asilites, the genera Trupanea and Ommatius are nearly limited to 



2* 



