1913] Agromyza and Cerodontha. 303 



28. Agromyza waltoni, new species. 

 Plate XXVIII, Fig. G; Plate XXXI, Fig. 36. 



Female: Frons black, center stripe opaque, orbits subshining, 

 glossy at base of bristles; breadth of frons slightly more than one-half 

 the head width, and almost subquadrate; orbits slightly differentiated 

 from center stripe, each at broadest part about one-fourth the breadth 

 of center stripe at same part, orbital bristles five in number, on one 

 side at margin of lunule is another smaller bristle which I take to be 

 abnormal; lunule brownish yellow, covered with white poUinosity; 

 ocellar region subopaque; posterior ocelli occupying about one-fifth the 

 width of vertex; antennas black, rather below average size; second 

 joint with apical bristles on outer side, the dorsal bristle distinct; 

 third joint rounded, barely longer than broad, not distinctly pilose; 

 arista black, paler at base, swollen on basal fourth, almost bare, in 

 length reaching almost from its base to upper orbital bristle; face and 

 cheeks black-brown; slightly gray dusted; the former in profile almost 

 perpendicular, center raised slightly, but not sharply keeled; cheeks 

 at posterior margin about one-sixth the eye height, anteriorly becoming 

 linear; marginal bristles strong, anterior two higher than vibrissa; 

 vibrissa strong; proboscis yellow; palpi black, slightly spatulate, bris- 

 tles weak. Mesonotum black, slightly shining, grayish dusted; four 

 pairs of dorso-centrals present, these are reduced in size anteriorly; 

 the setulce between the dorso-centrals in about 10 irregular rows, the 

 two bristles between posterior dorso-centrals distinct, separated from 

 each other by almost twice the distance between them and the dorso- 

 centrals; pleurae black, shining, sutures brownish; squamae brownish 

 yellow, fringe brown; scutellum and postnotum concolorous with 

 pleurae. Abdomen shining black. Sixth segment elongated; base of 

 ovipositor shorter than preceding segment; all segments with numerous 

 hairs, those on apices of segments, and especially the sixth, bristle 

 like. Legs black, shining; knees brownish; fore femur with long 

 ventral bristles; the posterior bristles on mid tibia present, but very 

 short in type. Wings yellowish brown at base ; subcostal vein complete, 

 rather distinct; second costal division slightly more than twice as long 

 as first; inner cross vein slightly beyond end of first vein, outer at 

 length of inner from that vein, and distinctly before wing middle, 

 veins 2-3-4 very noticeably divergent at apices; penultimate section 

 of fifth distinctly shorter than ultimate section. Halteres yellow, 

 knobs whitish. 



Length, 4 mm. 



Type: Cat. No. 15572, U. S. N. M. 



Locality: Long Lake, Adirondack Mountains, (Horvath). 

 One female. 



Food-plant unknown. 



Named in honor of Mr. W. R. Walton of the Bureau of 

 Entomology. 



