Since the publication of Whitehouse's Catalogue of the Odonata of Canada and Alaska (1) several papers on Canadian Odonata have appeared that have added to our knowledge of the composition and distribution of this order of insects in Canada. Two species have been added to the Canadian list, viz., Celithemis martha Wmsn. from Nova Scotia by Cook (2) and Somatochlora sahlbergi Trybom from the Mackenzie District N.W.T., by Walker (3). Cook adds also the following that are new to Nova Scotia: Enallagma cyathigerum Charp., Gomphus spicatus Hagen, G. ventricosus Walsh, Celithemis elisa Hagen, Libellula pulchella Drury, L. Lydia Drury and L. luctuosa Burm.; and one new to New Brunswick, Aeshna interrupta interrupta Walk. Walker (3) adds two to Labrador (Lestes disjunctus Selys and Libellula quadrimaculata L.), two to Manitoba (Somatochlora septentrionalis Hagen and Leucorrhinia patricia Walk.) and four to the Mackenzie District, N.W.T. (Lestes congener Hagen, Nehallenia irene Hagen, Somatochlora albicincta Burm. and Sympetrum obtrusum Hagen) besides Somatochlora sahlbergi, already mentioned. He also gives a list of 14 species from the Yukon Territory, from which only two species were previously known .

The physiochemical properties of the blood of an animal are maintained in a close equilibrium conducive to the normal functioning of the organism. Disturbances in the physiological functian may result in characteristic changes in the blood. For example, the specific gravity of normal human blood, which averages about 1.060, may vary with age, sex, nutritive condition, and disease (Hawk, Oser. and Summerson, 1947). The reaction of blood to metabolic and pathological conditions is recognized by the medical profession as a valuable aid in diagnosis (Scudder, 1939). Changes have been shown in the specific gravity of human blood in pregnancy and cancer (Polowe, 1932; 1934). It has also been shown that haemorrhage is accompanied by a decline in the specific gravity (Richet, Brodin, and Saint-Girons, 19 18).

The new forms described below constitute an interesting addition to the sarcophagine fauna of several western states and one eastern. I am indebted to the collectors indicated below for the privilege of studying the material accredited to them. Types of the new species based upon Kansas University material are returned for deposit in the Snow Entomological Collections as mentioned under the descriptions; all others are retained by permission in my collection.

Literature on grasshopper control published hetween 1930 and 1942 stressed the desirability of applying poisoned bait when grasshoppers begin their first main feeding period of the day. Such pubiications include those by Parker (1930). Parker, Walton, and Shotwell (1932), Criddle (1932). Ruggles and Aamodt (1938), and Bird (1940). Parker (1930) found that the lesser migratory grasshopper, Melanoplus mexicanus mexicanus (Sauss.), fed sparingly on baits at air temperatures between 55°F. and 63°F., more actively between 64°F. and 67°F., and most actively between 68°F. and 78°F. A rapid decrease in feeding occurred when air temperature rose above 80°F. or the soil surface temperature above 113°F. Much the same relationship held also for the clear-winged grasshopper, Cammula pellucida (Scudd.). On the basis of such observations it was decided chat an air temperature of 68°F. might be classed as optimum for beginning the application of bait. Parker did not, however, indicate the degree of mortality resulting from such feeding; the other writers gave no experimental data.