OLOSSAHY. XIU 



Ercmcchata. — A siiperf'amily in which Osten Sacken included the Stratki- 

 MYiD-E (with Xylomyin.k), Tabanid.e, AcANTiiOMERiD^, and Leptid.e 

 (with Xylopiiagin.e and Ccenomyin.e). Verrall adds to these the 

 Nemestkinid^ and C'yhtid.e. 



Eremochafoiis. — A term applied to those Diptei-a absolutely without any 

 strong bristles on the head or thorax, as distinct from ordinary 

 pubescence or such as the bristly hairs in PsYcnoDiDyE. 



Eucephala. — Those larva3 possessing a distinct head ; as opposed to tlie 

 Acepuala. 



Extricate. — Applied to pupre in which, from their mummy-like facies, tlie 

 outlines of the futui'e imago are more or less distinctly seen. 



Face, fades. — The term face is restricted to that part of the front of the 

 head below the antennae and enclosed by the cheeks and the upper 

 margin of the mouth. In many cases a well-defined line, ridge or 

 bend in the surface distinctly delimits the face ; at other times the 

 limits are formed by imaginary lines drawn between the points 

 specified. Fades literally means the face proper, as above described, 

 but is never used in that sense, being employed to signify the general 

 appearance of the whole insect. 



Facial ridge. — The sides of the antennal foveic. 



Fascia.— A. transverse mark which is more or less irregular in outline, 

 generally with ill-defined edges. 



Feet. — Some of the older authors, as late even as Walker and (sometimes) 

 Osten Sacken, used this term to signify the whole of the legs, but it 

 should strictly be applied to the appendages of the last tarsal joint. 

 The feet of Diptera consist of (1) two u)u/aes or claws (movable curved 

 opposable hooks), (2) the i^iUviUi, or two pad-like fleshy cushions, and 

 (3) the empodiiDn, a median appendage varying in form from an 

 additional pad to a spiny process. Sometimes the empodium is 

 pulvilliform, occasionally the pulvilli are absent, or modified. 



Femur. — The first conspicuous long joint of the legs, nearly always the 

 strongest of all ; preceded by the coxa and the very small connecting 

 joint between these two called the trochanter, and followed by the 

 tibia. 



Ferruginous. — A reddish brown with more or less of a yellowish tinge ; rust- 

 colour. Walker describes the word as " rusty yellow." Ridgway gives 

 it as " light burnt sienna." 



Flagellum. — The joints of the antenna after the basal two (which latter are 

 known as the scape). In the Nematocera they are nearly always 

 differently shaped from the scapal joints, and very variable in form 

 (p. 21). 



Forceps. — The term employed by Osten Sacken and some others for the male 

 genitalia in such families in which they are conspicuous, complex and 

 formed mainly of a pair of distinct claspcrs to which various appendages 

 are attached. 



Fovea, fovea. — See Antenncd groove. 



Frenulum. — A name suggested by Loew for what is generally known as the 

 scntellar ridge. 



