78 Orthonliapha liiacbyceia. 



thought to be xylophagous, and Drewsen has first shown (Nat. Tidsskr. 

 IV, lO:!. 1842-43) that they are carnivoroiis: wlien several laivæ are 

 hold together in capitivily. some of theni generally devour tlie others. 

 The larvæ hibernate and develop in summer. 



The species of Xylophagus occur, in accordance with the occuirent-e 

 of their larvæ. in the outskirts of woods on stems and stubs, and they 

 are rather lively; the seem to use their legs more than the wings. 



Of the genus two palæarctic species are known one of which occurs 

 in Denmark. 



1. X. ater Meig. 



1804. Meig. Klass. zweifl. lus. 1, 154, 1, T. IX, Fig. 2. — 1842. Zett. 

 Uipt. Scaud. I, 128, 1. — 1843. Schiødte, Naturh. Tidsskr. IV, 103. — 

 1862. Schin. F. A. I, 27. — 1903. Kat. palaarkt. Dipt. 11, 41. 



Male. Vertex somewhat impressed. front black above the antennæ. 

 towards the vertex greyish pruinose, epistoma of the same colour; palpi 

 with the first joint yellow, tlio second black. Eyes with the facets 

 siightly larger towards the inner margin. Antennæ dark brownish or 

 brownish black. Thorax black, somewhat shining in the middle. towards 

 the sides dull and tinely striated, sterna and pleura black, shining. The 

 humeral and postalar calli somewhat prominent, brownish: scutellum 

 often somewhat brownish, especially towards the sides. Tiie disc of 

 the thorax sparingly clothed with short, yellow hairs in the middle, 

 the hairs forming two indistinct stripes. Abdomen black, shining, with 

 somewhat longish, greyish hairs. Legs yellow ; the hind tibiæ towards 

 the tips and the tarsi towards the ends dark brown to blackish; the 

 hind femora may also be somewhat darkened at the ends. Wings 

 hyaline with a brownish stigma; from the base of the cubital veiu 

 and downwards on the postical cross-vein there is a slight fumi- 

 gation. and a similar at the base of the cubital fork and at the apex 

 of the discai ceil; the veins brown. Halteres yellow. 



Female. Thorax with three broad, greyish pruinose bands, between 

 these two shining lines with short hairs. Al>domen longer and tiiicker 

 I han in the male, pointed, ending in a .slender ovipositor. Wings 

 yellowish with the fumigations more disfinct and more extended than 

 in the male. 



Length. Tliis species varies mucli in size, and moreover the 

 females are larger than the males; length of male 7,5 — 10,5 mm., of 

 female 10,5—14 mm. 



X ater is not rare but imagines are generally only taken in small 

 nunibers or single specimens: Ermelund, Dyrehaven, Bøllemosen, at 

 Sorø and at Thureby; Lolland at Maribo and Ryde; Langeland; Jutland 



