133* BIRDS OF ILLINOIS. 



There are two strongly marked subgenera, which may be dis- 

 tinguished as follows: 



a 1 . Culmen about as long as the tarsus; gonys nearly straight, and lateral outlines of the 

 bill slightly concave; tarsus but little longer than middle toe; scapulars normal (i. e. 

 broad and blended) Nycticorax. 



a 2 . Culmen much shorter than tarsus (only a little longer than middle toe); eonys convex, 

 and lateral outlines of bill straight, or sometimes even perceptibly convex; tarsus 

 much longer than middle toe; scapulars elongated, narrow (but not pointed), some- 

 what loose-webbed Nyetanassa. 



SUBGENUS Nycticorax STEPHENS. 



Nycticorax STEPHENS, Shaw's Gen. Zool. xi, 1819, 608. Type, Ardea 

 Nyctiardea SWAINS. Classif. B. ii, 1837, 351. Same type. 



SUBGEN. CHAE. Medium-sized Eerons of very short thick build, large.'thick heads, and 

 short tarsi. The plumage exceedingly different in the adult and young, but the sexes sim- 

 ilar. Adults with two or three exceedingly long, thread-like, white occipital plumes. 



Bill very stout, the depth through the base being more than one fourth the culmen; 

 the latter nearly straight for the basal two thirds, then gently curved to the tip ; lower edge 

 of the mandibular rami nearly straight; gonys nearly straight, very slightly ascending; 

 maxillary toinium decidedly concave, with a very convex outline just forward of the rictus. 

 Mental apex reaching more than half-way from the centre of the eye to the point of the bill, 

 and to beyond the anterior end of the nostril ; malar apex falling a little short of the frontal 

 apex. Tarsi a little longer than the middle toe, its scutellce hexagonal in front; lateral 

 toes nearly eaual, but the outer the longer; hallux less than half the middle toe; bare 

 portion of tibia Shorter than the hallux. Inner webs of two outer primaries distinctly 

 emarginated near the end. Tail of twelve broad, moderately hard, feathers, as in the typ- 

 ical herons. 



Nycticorax nycticorax naevius (Bodd.) 



BLACK-CROWNED NIGHT HEEON. 



Popular synonyms. American Black-crowned Night Heron; Quok; Quawk; Quak; Qua 

 Bird; Inanite pinto elote (Mexico). 



Ardea ncevia BODD. Tabl. P. E. 1783, 56 (ex PL Enl. 939). 



Nyctiardea grisea var. ncevia ALLEN, Bull. Mus. Comp. Zool. iii, 1872, 182. COUES, 



Key, 1872. 269; Cheek List, 1873, No. 458; B. N. W. 1874, 523. 

 Nyctiardea grisea ft ncevia BIDGW. Orn. 40th Par. 1877. 

 Nyctiardea grisea ncevia BIDGW. Nom. N. Am. B. 1881, No. 495. COUES, 2d Check 



List, 1882, No. 604. 



Nycticorax griseus ncevius B. B. & B. Water B. N. Am. i, 1884. 55. 

 Nycticorax nycticorax ncevius ZELED. Proc. U. S. Nat. Mus. viii, 1885, 113. A. 0. U. 



Check List, 1886, No. 202. BIDGW. Man. N. Am. B. 1887,133. 

 Ardea hoactle GMEL. S. N. i, pt. ii,1788, 630. 

 Ardea cana GMEL. t. c. 643. 

 Ardea gardeni GMEL. t. c. 645 (based on Gardenian Night Heron of PENNANT and 



LATHAM). 



Nyctiardea gardeni BAIED, B. N. Am. 1858, 678; Cat. N. Am. B. 1859, No. 495. 

 Ardea discolor NUTT. Man. ii. 1834, 54. 



