132 THE CANADIAN ENTOMOLOGIST 



11. Large, robust species, 4 mm. in length; general colour shin- 

 ing black. Larvae mining cambium of Pruniis 



domestica. N. Y pruni Grossenbacher. 



Smaller, slender species, 2 mm. in length; general colour black, 

 slightly shining. Food-plants unknown. 

 Alaska : parvicella coquillett . 



Agromyza indecora, sp. n. 



Male and Female. — Black, shining. Frons opaque, orbits and 

 ocellar triangle shining. Legs black. Wings clear, veins black. 

 Halteres brown, knobs whitish yellow. Squamae grayish, fringes 

 blackish. 



Orbital bristles strong, usually 6 in number; antennae of 

 moderate size, third joint rounded apically; arista swollen at base, 

 microscopically pubescent; cheek narrow, its height about half as 

 great as width of third antennal joint. Mesonotum with numerous 

 short discal setulae and 4 strong dorso-centrals ; the pair of bristles 

 between posterior dorso-centrals well developed. Abdomen stout. 

 Legs stout, the pair of posterior bristles on mid-tibia very unequal 

 in size. Costa ending just beyond apex of third vein; third and 

 fourth veins very noticeably divergent apically; inner cross- vein 

 usually at middle of discal cell or slightly beyond that point; outer 

 cross-vein below apex of first vein; last section of fifth \ein 2 to 

 234 times as long as preceding section. 



Length 2.5-3.5 mm. 



Type locality. White Heath, 111., June 24, 1916; June 29, 

 1917; (J. R. Malloch). Food-plant unknown. 



This species is closely related to priini Grossenbacher, but 

 may be separated from it by the venation. This character is 

 usually a rather unstable one, but my series of pnini contains no 

 example with the last section of the fifth vein approximating to 

 twice the length of the preceding section, while in the large series 

 of indecora there is no specimen which has the last section of that 

 vein less than twice as long as the preceding section. The inner 

 cross-vein in indecora is usually but little beyond the middle of the 

 discal cell, whereas in pruni it is generally one-third from apex of 

 the cell. The third and fourth veins in pruni are but little divergent 

 apically; in indecora they are strongly divergent. 



