Since 1923 the writer has operated a light trap at Bozeman for the purpose of recording fauna and seasonal fluctuations in the population of Phalaenid moths. This trap, known as the “Field Trap,” is located on the east edge of a large agricultural experimental field which is cut into many plots. The trap is about 100 yards west of the nearest building, and is on a pole with the light about six feet above the ground.

Late in the summer of 1926, several adults of the beetle (Microrhopala vittata Fabr.) were found in the blistered portions of leaves of the compass plant (Silphium laciniatum L.). The insect is black with head and thorax red and with red stripes on the second costa and at the outer margin of each elytron. It is subdepressed and about 6 mm. long.

The genus Polmacorixa was erected by Abbott (Ent. News, XXIII, 337, 1912) for a single species, Palmacorixa gillettii Abb. described from three males and three females collected at Fort Collins, Colorado, during May and June, by Professor C. P. Gillette. Subsequently (Can. Ent., XLV, 113, 1913) Dr. Abbott described a second species, Palmacorixa buenoi Abb. from specimens taken at White Plains, New York, during August and September, by Mr. J. R. de la Torre-Bueno. A third species, Palmacorixa mexicana Hungfd. has been described by Dr. H. B. Hungerford (Pan-Pac. Ent., IV, 94, 1927) from a pair of specimens collected in the Xochimilco Sea, Mexico, by Dr. A. Dampf.

The following list is compiled from specimens collected by Mr. W. J. Brown in 1929; it should prove of interest to students of geographical distribution, containing, as it does, large elements of the Labrador fauna on the one hand and typical members of the Canadian and Hudsonian zones on the other. As far as I know Wm. Couper has been the only one who has published on the Lepidoptera of this region (Can. Ent., I, 67; IV, 201; VI, 33 et seq.) and his work has been confined largely to diurnals.