1913] Agromyza and Cerodontha. 283 



Agromyza melampyga var. marginalis, new variety. 

 Male and Female: This variety differs from the type in being 

 rather smaller 13^ mm.; in being comparatively more strongly bristled, 

 in having only the margins of the thoracic markings black, the remain- 

 der being yellowish, and in having the arista shorter, barely reaching 

 to vertex in the only specimen in which it is extant. 



The three specimens, two males, one female, were reared 

 from Paspalurii, (Oct. 2, 1912). Locality: Columbia, South 

 Carolina, (P. Luginbill) Webster, No. 9711. 



Type: Cat. No. 15561, U. S. N. M. 



It is possible that this is a distinct species, but the material 

 is too scanty to give one a basis for a definite opinion as to- 

 whether it is so, or whether the eifect of a different food plant, 

 is responsible for the variation in color, etc. 



-9. Agromyza brevicostalis, new species. 

 Plate XXVIII, Fig. S. 

 Female: Frons lemon yellow; one half as broad as head and dis- 

 tinctly broader than long; center stripe blackened on anterior half; 

 orbits differentiated from center stripe; four orbital bristles present; in 

 addition to the bristles there is a row of weak hairs nearer to eye 

 margin, which begins at opposite base of antennae and continues to 

 beyond upper orbital bristle; ocellar region raised, brown; back of 

 head, and a triangular patch at lateral angle of orbits brown, or black- 

 brown; lunule yellow; antennse of moderate size, black brown; second 

 joint with distinct dorsal bristle; third joint rounded in front, covered 

 with short pilosity; arista brown; basal swelling elongate; pubescence 

 very indistinct; length of arista equal to from its base to upper orbital 

 bristle; face yellow, blackened on depressions below antennas; concave 

 in profile; keel slight; cheeks yellow, blackened anteriorly; distinctly 

 higher posteriorly than anteriorly; height at highest part less than one- 

 half the height of eye; occiput not projecting on upper half; proboscis 

 yellow; palpi black, nonnal. Mesonotum gray black, subopaque, 

 broadly pale yellow on lateral margins; a small patch on each side 

 posteriorly, the pale color extending slightly on to anterior lateral 

 angle of scutellimi; four pairs of dorso-centrals present, the anterior 

 two pairs reduced in size; no distinct dorso-centrals anterior to suture, 

 though the 3 setulas immediately anterior to suture in line with dorso- 

 centrals are rather strong; discal setul« upright, not very numerous; 

 about 4 irregtdar rows between the dorso-centrals; the pair of bristles 

 between the posterior pair of dorso-centrals distinct, and of moderate 

 length; humeri yellow, with a dark discal mark; pleurae black-gray, 

 subshining; sutures and upper margin narrowly, and a patch below 

 wing base yellow; squamae yellow, fringe brown. Abdomen glossy 

 black, posterior margins of all segments narrowly pale yellow ; segments 

 with numerous hairs, stronger on posterior margins; base of ovipositor 

 glossy black, as long as preceding segment. Legs black, glossy, knees 



