133* , BIRDS OF ILLINOIS. 



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

 tinguished as follows: 



ffli. Oulmen about as long as the tarsus; gonys nearly straight, and lateral outlines of the 

 bill slightly oonoave ; tarsus but little longer than middle toe ; scapulars normal (i. «. 

 broad and blended) '. .T .....Hyctioorax. 



o". Oulmen 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), «ome- 

 what loose- webbed ITyetanaBsa. 



Subgenus Nycticorax Stephens. 



Wt/ctieorax Stephens, Shaw's Gen. Zool. xi, 1819, 608. Type, Ardea nvBticcraalirss. 

 Nyctiardea Swains. Olassil, B. ii, 1837, 35j. Same type. 



SuBGEN. Chab. Medium-sized Herons of very short thick build, large,'thlok 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 oooipltal pl'imes. 



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

 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 tomium 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 scutellw hexagonal in front; lateral 

 toes nearly euual, 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 

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

 ical herons, 



Nycticorax nycticorax naevius (Bodd.) 



BLACK-CBOWNED NIGHT HEBON, 



Popular synonyms. American Black-crowned Night Heron; Quok; Qu5,wk; Quak; Qua 

 Bird; Inanite pinto elote (Mexico). 



Ardea nwvia Bodd. Tabl. P. E. 1783, 56 (ex PI. Enl. 939). 



Nyctiardea grisea var. nwvia AiOLEN,' Bull. Mus. Oomp. Zool. iii, 1872, 182.— CouES, 



Key, 1872, 269; Check List, 1873. No. 458; B. N. W. 1874, .'>23. 

 Nyctiardea grisea /S ncEvia'RiDaw. Cm. 46th Par. 1877. 

 Nyctiardea grisea nasvia Eidgw. Nom. N. Am. B. 1881, No. 495.— CotrEs, 2d Check 



List, 1882, No. 664. 

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

 Nycticorax nycHeorax noevius Zelbd. Proo. U. S. Nat. Mus. viii. 1,886, 113.— A. O. U. 

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

 Ardea hoactU Gubl. S. N- i> Pt. ii,1788, 630. 

 Ardea cana Guel. t. o. 643. 



Ardea gardeni Gmel. t. o. 615 (based on Qardenian Night Heron of Pennant and 

 Late AM), 

 Nyctiardea gardeni Baibd, B. N. Am. 1868, 678; Oat. N. Am. B. 1859, No, 49S, 

 Ardfa (Mvol^r'&VTf- -Uan, il,1834,fil. 



