Gavia immer immer (Brünnich)
Other Names.—Great Northern Diver; Loom.

Description.—Size large; bill long and sharp; tail very short, with legs sticking out behind. Adults in spring: Upperparts black, with bluish and greenish reflections; patches on throat and sides of neck streaked with white; back and wings marked regularly with rows of white squares; underparts silvery white; sides black, spotted finely with white; eyes red. Immature birds and adults in winter: Upperparts blackish, margined with gray and without white spots; throat and neck grayish; underparts white. Length: about 30 inches.