Digonochaeta. 449 



joint twice as long as second or more; arista with second joint elong- 

 ated {enigmatica) or with both first and second elongated (setipennis); 

 the joints are geniculate towards each other. Thorax rectangular 

 or nearly quadratic; three postsutural dorsocentrals, and two or 

 three præ- and three postsutural acrostichals ; no præsutural intraalar 

 bristle. Scutellum with three marginal bristles on each side, and a 

 pair of small apical, parallel or diverging hairs; a pair of discai bristles. 

 Three sternopleural bristles. Pteropleura hairy, with a bristle above. 

 Abdomen ovate; excavation on second segment reaching hind margin 

 (setipennis) or not {enigmatica); there are discai and marginal bristles, 

 second segment without bristles. Legs somewhat short and robust, 

 anterodorsal bristles on hind tibiæ unequal; claws and pulvilli in 

 male not elongated and front tarsi in female simple. Wings with 

 first posterior cell open or just closed, ending at or just before apex 

 of wing; discai angle obtuse; posterior cross-vein m middle between 

 medial cross-vein and angle or anterior to it; cubital vein with bristles 

 beyond medial cross-vein; subcostal and postical vein bare {enig- 

 matica) or the former spinulose in the whole length, the latter on 

 basal part {setipennis); a somewhat small or quite minute costal spine. 



The biology of setipennis is known, it is especially parasitic on 

 Forficulids, but also on a number of Heterocera (perhaps intermediate 

 hosts). According to Pantel it belongs to his group 5, and it forms 

 a primary breathing hole. For enigmatica only a lepidopterous host 

 is known, but its biology is otherwise unknown. After Nielsen's observ- 

 ations (se under the species) it does not seem to belong to Pantel's 

 group 5. 



Of the genus four or five species are known, two occur in Den- 

 mark. 



Table of Species. 



1. Cheeks with numerous hairs; arista with first joint short, 

 second elongated; abdomen with excavation on second 

 segment small, not reaching hind margin ; only cubital vein 

 with bristles [Goniocera B. B.) 1. enigmatica. 



— Cheeks with a single row of hairs; arista with both first 

 and second joint elongated; abdomen with excavation on 

 second segment reaching hind margin; subcostal, cubital 

 and postical vein with bristles {Digonochaeta s. str.) 2. setipennis. 



1. D. enigmatica Villen. et Niels. 



1917. Villen. et Niels. Vidensk. Medd. fra Dansk naturh. Foren. 68, 32 

 (Goniocera). — ? Goniocera schistacea B. B. 1891. Denkschr. Akad. Wiss. Wien, 

 LVIII, 354. 



29 



