336 CLASS vin. 



without occasioning much confusion. LIKNJEUS referred these flies 

 to the genus Musca. By their antennae they approach the last 

 family of the diptera, the Nemocera, in which there is constantly 

 found a great number of joints, whilst the rest of the families have 

 ordinarily three alone. At the same time the majority of writers 

 consider the antennae of the Notacantha to be three-jointed in like 

 manner, in which view the last joints are merely noted as rings in 

 the terminal joint. But there is much that is uncertain and arbi- 

 trary here. That the seta of the Athericera may be counted as a 

 joint of the antenna, and that it is not separated by any sharp 

 boundary from a stylus, which is itself often jointed also, will be 

 readily admitted by every one who has not studied nature from 

 books alone. The true place of the Notacantha in a natural system 

 cannot in any case be far from Tabanus, although some only agree 

 with Tabani in the metamorphosis, the genus Pachystomus for in- 

 stance (LATKEILLE Genera Crust, et Ins. iv. pp. 286, 287), the properly 

 so-named Xylophagi, and perhaps Co&nomyia (see WESTWOOD, Introd. 

 to modern Classif. of Insects, n. p. 535). Most of the species, on the 

 other hand, the species of all the genera which establish the essen- 

 tial type of this family, do not cast their skin. Under the skin of 

 the larva, which however does not, as occurs in Athericera, contract 

 itself to a ball, the pupa is formed. Some larvae live underground, 

 others in decayed wood, others in water. 



The antennae are mostly cylindrical or conical, sometimes club- 

 shaped, and seldom longer than the head ; this last is a semi-round, 

 of which the eyes in the male occupy almost the whole bulk; there 

 are three ocelli. The body is flat ; the wings are long and cross 

 one another, lying flat on the abdomen, and mostly leaving its sides 

 uncovered. 



A. Antennas mostly with ten joints, the last eight confluent into 

 a single subulate body, style none. 



t Antennae not longer than head. 



Ccenomyia LATR. (Sicus FABR.) Scutellum bidentate. 



Sp. Ccenomyia ferruginea MEIG., Europ. zweifl. Ins. II. Tab. 1 2 ; DUMER. 

 Cons. gin. s. I. Ins. PI. 48, fig. 3. 



XylopJiagus MEIG. Scutellum unarmed. 



Xylophagus WESTW. First joint of antennae elongate. 



Sp. Xylophagus ater MEIG., Europ. zweifl. Ins. n. Tab. 12, fig. 14; Empis 

 subulata PANZEB, Deutschl. Ins. Heft 54, no. 23. 



