"The young birds are very like the female, as determined by Mr. Oates and myself, but the whole back is variegated with yellowish-buff spots and markings, as well as the wings, so that the uniform brown mantle is a sign of the adult female, and the spotted mantle of a young bird. Mr. Everett gives the soft parts of a young female as follows: 'Legs and feet bright olive-green; bill greenish yellow at base, the culmen of a dark olive-brown tint; iris golden yellow.' "Considerable variation in the tint of the cinnamon plumage of this species is observable in a series, and specimens from more southern localities are decidedly the darker and richer in color." (Sharpe.) Genus NANNOCNUS Stejneger, 1887. Very similar to Ixobrychus but the lower part of tibia unfeathered and the quills and tail-feathers blackish. 151. NANNOCNUS EURHYTHMUS (Swinhoe). SCHRENCK'S BITTERN. Ardetta eurhythma Swinhoe, Ibis (1873), 74, pl. 2; Meyer and Wiglesworth, Birds of Celebes (1898), 2, 856, pl. 45. Nannocnus eurythmus Sharpe, Cat. Birds Brit. Mus. (1898), 26, 242; Hand-List (1899), 1, 203; Oates, Cat. Birds' Eggs (1902), 2, 133; McGregor and Worcester, Hand-List (1906), 35. Mindanao (Bourns & Worcester); Negros (Keay). Eastern Siberia, China, Japan, Borneo, Celebes. "Adult male.--Above chestnut-brown; lesser wing-coverts and feathers round bend of wing also chestnut-brown; alula-feathers chestnut, outer ones blackish internally, with white on the outer margins; remainder of wing-coverts olive-clay-color, ashy near the ends of the feathers, innermost greater-coverts chestnut like scapulars; innermost secondaries also washed with chestnut, remainder of quills and primary-coverts ashy brown, paler at the tips, which are fringed with whitish, the first primary margined with ocherous; tail dark brown; crown and nape dusky brown; sides of face, ear-coverts, and neck-frill maroon; a broad band of white running from the middle of the cheeks down the sides of the neck; fore part of cheeks, throat, and under surface of body ocherous-buff; under tail-coverts, under wing-coverts, and axillars white; on the throat some slight indications of longitudinal dusky spots; feathers of the fore neck elongated; on each side of chest a patch of black feathers with ocherous margins. 'Bill blackish brown on culmen, yellowish brown on the rest, darker on the sides of upper mandible near tomia, light on sides of lower and on gonys; cere and bare skin round eye purplish flesh-color, ringed with green; legs and toes grass-green, yellow near the tarso-tibial joint and on the under surface of the tarsus; soles clay-colored; claws light yellowish brown; iris straw-color.' (Swinhoe.) Length, 305; culmen, 50; wing, 150; tail, 39; tarsus, 51.