TABANIDTIv 49 



15. ACANTHOMERID^. 



Very large, the largest among diptera, stout, bristleless, 

 nearly bare flies. Eyes large, contiguous in the male. Ocelli 

 present. Third joint of tlie anteniue complex, composed of 

 seven segments, with a terminal, often in the male setiform 

 style. Proboscis short, not adapted for piercing, with fleshy 

 labella. Tegular rudimentary. Tibiffi without spurs ; pulvilli 

 and empodia pad-like. Wings with two submarginal and Ave 

 posterior cells, the fourth posterior cell and the anal cell closed. 



But two genera are known in this family, including alto- 

 gether only about flfteen or sixteen species, all of which are 

 inhabitants of Central and South America. The species are 

 remarkable for their extraordin;iry size, some reaching nearly 

 two inches in length. The species of Acanthomera are found 

 in forests, alighting on trunks of trees, according to Mr. 

 Champion; otherwise their habits, whether of the adult or 

 immature stages, are but little known. Brauer has figured 

 and described the larvae of A. Frauenfeldii. They are cylin- 

 drical, thick and short. The last segment is firmly chitinized 

 above with two series of booklets, the two projecting back- 

 wards in the middle being stout and curved ; below these 

 there is a deep, transverse cleft, on the under side of which is 

 a roimded lip. 



In both Acanthomera and Ii/iaj)Inor//i/nr/nis the face may be 

 produced conically or not at all. Tlie two genera are distin- 

 guished by the structure of the pal})i, in Acanthoviera slender, 

 in lUiajjJiiorJiijnclius stout and pointed. AcanthAmiera may 

 have spines on the hind femora. 



IG. TAP>ANID.E. 



Head large, transverse, somewliat flattened and with the 

 occiput flat or concave. Antennae porrect, the tliird joint com- 

 posed of from five to eight annuli or segments. Eyes large, 

 pubescent or bare, contiguous above in the male and with the 



