DURHAM DIPTERA. 309 



XXXV. 502. 



2 (1). Third antennal joint nearly round, not longer than 



the second ; head much narrower than thorax. 



3 (4). A large (6-7 mm.) brownish black shore fly with 



reddish antennae ; the abdominal segments tawny 



along the hind border, and with a tawny spot on 



each side. 



505. Fucomyia, Hal. (2250. frigida, Fin.) 



4 (3). A smaller (4-5 mm.) brownish black fly with the third 



antennal joint dark. 



504. Cgelopa, Mg. (2248. pilipes, Hal.) 



Family XXXVL— HELOMYZID^. 



TABLE OP GENERA (after Lcew). 



1 (2). Humeral bristle absent. Helomyza, Fin. (506) 



2 (1). Humeral bristle present. 



3 (4). Prothoracic bristle absent. 



507. Allophyla, Lw. (2267. atricomis, Mg.) 



4 (3). Prothoracic bristle present. 



5 (6). Spurs of the mid tibiae bent ; species with long and 



soft hair. 



508. Scoliocentra, Lw. (2268. villosa, Mg.) 



6 (5). Spurs of the middle tibiae straight ; neither long nor 



soft haired. 



7 (8). X,4. directly beneath the end of V.I .a. 



Crymobia, Lw. (hiemalis, Lw.) 



8 (7). X.4. far beyond the end of V.I .a. 



9 (12). Eyes unusually small. 



10 (11). Mid tibiae without bristles. Eccoptomera. Lw. (510) 



11 (10). Mid tibiae with bristles. 



599. CEcothea, Hal. (2269. fenestralis, Fin.) 



12 (9). Eyes not unusually small. 



13 (14). V.l.b. unusually lengthened, and ending in the costa 



far beyond X.4. ; costal spines very short ; frons 

 narrow ; praesutural bristles present. 



Heteromyza, Fin. (5 IS) 



14 (13). V.l.b. of normal length, ending in costa nearly in a 



line with X.4. ; costa distinctly spined ; frons broad. 



