133* lilRDS OP ILLINOIS. 



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

 tinguished as follows: 



o'. 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) Hycticorax. 



a'. Culmen much shorter than tarsus (only a little longer than middle toe); gonys 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 Nyctanassa. 



Subgenus Nycticorax Stephens. 



NycHcorax Stephens, Shaw's Gen. Zool. xi, 1819, 608. Type. A rdea nycttcrrax Lnm. 



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



SuEGEN. Chab. Medium-sized Herons of very short thick build, large,'thick heads, and 

 short tarsi. The plumage exceedingly diflferent iu 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 f oiu-th the culmen; 

 the latter nearly straight lor the basal two thirds, then gently curved to the tip; Ic wer 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 thanhalf-way from the centre of the eye to the point of the bill, 

 and to beyond the anterior end of the nc-stril; malar apex falling a little short of the frontal 

 apex. Tarsi a Uttle longer than the middle toe, its sciitelhv hexaoonal in front; lateral 

 toes nearly equal, but the outer the longer; hallux less than halt the middle toe: bare 

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

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

 ical herons. 



Nycticorax nycticorax nsevius (Bodd.) 



BLACK-CROWNED NIGHT HEEON, 



Popular synonyms. Ame ican Black-crowned Night Heron; Quok; Quawk; Ouak; Qua 

 Bird; Inanite pinto elote (Mexico). ^ 



Ardea na:via BoDD. Tabl. P. E. 1783, 56 (ex PI. Enl. 939). 



Nyctiardea grisea var. nrnvia Allen. Bull. Mus. Comp. Zool. iii, 1872, 182.— CoUES, 



Key.1872, 2(;9; Check List. 1873, No. 158; B. N. W. 1874. .-.23. 

 Nyctiardea grisea p nwoia Ridgw. Orn. 40th Par. 1877. 

 Nyctiardea grisea ncevia Ridgw. Norn. N. Am. B. 18S1, No. 495.— CouES, 2d Check 



List, 1882, No. 604. 

 Nycticorax griseus ncevius B. B. & R. Water B. N. Am. i. 1SS4. .'6. 

 Nycticorax nycticorax na:viiis Zeled. Proo. U. S. Nat. Mus. viii, 18S5. 113.— A. 0. U. 

 Check List. 1886, No. 20:;.— Bidow. Man. N. Am. B. 1887.133. 

 Ardea hoactle Gmkl. 8. N. i, pt. ii.l788. G30. 

 Ardea cana Gmel. t. o. 643. 



Ardea gardeni Gmel. t. c. CIS (based on Onrdenian Night JTeron of 1»enn.\nt and 

 Latham). 

 Nyctiardea garden i Baird, B. N. Am. 1S58, 67S; Cat. N. Am. B. 1859, No. <9S. 

 Ardea discolor Nun. Uau. ii, 1834, M, 



