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pass through a given locality. The difficulty is further heightened when it is 
remembered that some of the migratory birds pass by us without so much as 
lighting, and in the night-time at that. 
While speaking of migrations, it might here be noted that some of those 
species which are comparatively uncommon or rare during the fall migrations are 
common or abundant during the spring migrations, and vice versa. ‘To my knowl- 
edge a satisfactory explanation of this has never been given, though it would 
seem probable, amongst those species where this is true, that there is a difference 
between the lines of migration pursued by the fall migrants and those of spring. 
Again there are other species which are sometimes resident and sometimes 
migratory, being swayed back and forth by extremes of temperature. Also those 
species some individuals of which are always resident and some always migratory. 
But these facts will be duly exemplified in the list which is now submitted. 
1. Podilymbus podiceps (Linn.) Pied-billed Grebe. 
Found occasionally on our streams and ponds. 
2. Urinator imber (Gunn.) Loon. 
Sometimes observed during migrations. One was killed on the reservoir, east 
of Richmond, on April 8, 1897. 
83.  Hydrochelidon nigra surinamensis (Gmel.) Black Tern. 
During the heavy freshet of last summer (1896) a flock of these birds was 
observed in the neighborhood of Thistlewaithe’s pond, north of Richmond. 
4, Anas boschas (Linn.) Mallard, ‘‘ Wild Duck.” 
Common during the migrations, when flocks of them frequently settle down 
for several days. 
5. Anas discors (Linn.| Blue-winged Teal. 
A moderately common migrant. 
6. Branta canadensis (Linn.) Canada Goose. 
A common migrant; arrives generally about the first of March and begins to 
pass through on its southward flight during the latter week in October. 
7. Botaurus lentiginosus (Montvg.) American Bittern. 
A by no means common bird in this vicinity, but often found during the 
migrations. 
8. Ardea herodias (Linn.) Great Blue Heron. 
A rather uncommon bird in this locality and I have yet to find it breeding. 
9. Ardea candidissima (Gmel.) Snowy Heron. 
Stragglers are occasionally noted. One this spring (1897) on April 27. 
