1. S. sialis. No chestnut on the back; throat reddish;
abdomen and crissum white.
Blue of a rich dark purplish shade. Tail about 2.75. _Hab._
Eastern Province United States, Cuba, and Bermudas …
var. _sialis_.
Blue of a greenish shade. Tail about 3.20. _Hab._ East
Mexico and Guatemala … var. _azurea_.[26]
2. S. mexicana. Chestnut, in greater or less amount, on the
back; throat blue; abdomen and crissum blue. _Hab._ West and
South Middle Province United States, south to Jalapa,
Cordova, and Colima.