DURHAM DIPTERA. 249 



XXXIII. 450. 



5 (4) (8). Abdomen with well defined black or brown dorso- 



lateral spots. 



6 (7). Spots rounded ; X.4. and X.5 2 clouded. 



1947. Hyedotesia lucorum, Fin. 

 Escomb, 3 $ and 1 ?, Bishop Auckland, 1 $, Gibside, 

 1 $, Stanhope, 1 $, Hesleden, 1 $, March-May, 

 1898-1901. 



7 (6). Spots angular ; X-veins only slightly clouded. 



1953. Hyedotesia obscurata, Mg. 

 Wynyard, 1 $, May, 1902. 



8 (4) (5). Abdomen with indefinite spots and reflections. 



9 (10). Thorax with four post-sutural bristles. 



1948. Hyedotesia marmorata, Ztt. 

 Wearhead, 1 ?, August, 1901. 



10 (9). Thorax with three post-sutural bristles. 



1949. Hyedotesia serva, Mg. 

 Escomb, 1 $, Evenwood, 1 ?, May, 1897-1899 ; 

 Bishop Auckland, 2 $ and 2 ?, June, 1902. 



11 (3). Arista rather short haired (subplumose). 



12 (13). Abdomen marked with subquadrangular spots ; wings 



blackish. ( I 95°« dispar, Fin.) 



(Note. — Herr Stein -writes me that dispar, Fin., is not a Hyedotesia but 

 a Spilogaster, or better a Limnophora). 



13 (12). Abdomen with reflections ; wings clear. 



(195 1. goberti, Mik.) 



14 (2). Thorax indistinctly striped or unstriped. 



15 (23). Abdomen grey. 



16 (20). Abdomen oval, or nearly so. 



17 (18) (19). Abdomen spotted. 



1950^. Hyedotesia nivalis, Rnd. 

 Wearhead, 1 $, August, 1901. 

 This is the fly described by Schiner as dispar, 



which, Herr Stein writes me, is identical with H. 



nivalis, Rnd., and is very common about Genthin. 



Whether, he adds, it agrees with nivalis, Ztt., or 



not, cannot be ascertained, as the type is very 



badly preserved. 



