AKT. 10 NOETH AMERICAN TACHINID FLIES WEBBER 11 



ment inseparable on any characters known to the writer. In all 

 of the material examined, the puparia (fig. 12) appear similar, the 

 posterior spiracles are situated on about the same plane as the hori- 

 zontal axis, and the slits vary in number and arrangement. 



2. ACHAETONEURA EUCHAETIAE, new species 



Differs from A. frenchii (Williston) in that the male genitalia 

 are larger and of a different structure; thorax and abdomen more 

 grayish pollinose; front pulvilli of male shorter; posterior spiracles 

 of puparium situated some distance above longitudinal axis. 



Front of male at vertex varying from 0.33 to 0.35, in female 0.32 

 to 0.35 the head width; at base of antennae, front of male 0.44 to 

 0.46, in female 0.41 to 0.47 the head width; buccal width varying 

 from one-tenth to one-seventh the eye height; third antennal joint 

 in male from four and one-half to five and one-half, in female from 

 four to five times the second. Front in both sexes projecting be- 

 yond eye from one-half to three-fourths the eye width (head held 

 in profile, measurement taken at base of antennae). 



Front pulvilli of male about equal in length to the last tarsal 

 joint. Hind cross-vein sinuate, distance from its end to small cross- 

 vein varying from one-half to twice its length; distance from end 

 of hind cross-vein to angle of fourth vein equal to or considerably 

 less than its length. Apical cell open, third vein with two or three 

 bristles at base. 



Face and front cinereous, the latter usually with yellowish cast; 

 facial depression deep and more than three times wider than the 

 width of one parafacial at narrowest part, which is at this point 

 wider than the width of the third antennal joint. Occiput swollen 

 below. Antennae in both sexes black, seldom even faintly reddish 

 at base. Facial ridge bristles irregularly placed and often appear- 

 ing as a double row. Frontal bristles variable in number, usually 

 six or seven. Front of male densely beset with small bristles none 

 of which equals in size those of the frontal row. Thorax and abdo- 

 men black, gray pollinose, usually sub-shining; thoracic chaetotaxy 

 as in frenchii. Abdomen black, gray pollinose, anal segment densely 

 so, never golden. First three segments bearing only marginal 

 macrochaetae, the fourth moderately bristly on the apical three- 

 fourths. Mid tibiae with one strong and one weak or two strong 

 bristles on the outer front side; as in frenchii there are also two 

 hind bristles and a strong inner one present on the mid tibiae. Hind 

 tibiae evenly ciliate with one longer bristle. 



Genitalia (figs. 3, 4) much larger than in the typical frenchii. 

 Forceps viewed from behind, at widest part more than one-third 

 their length ; inner forceps fused at base and furnished with a very 



