826 SYSTEMATIC SYNOPSIS OF FOSSIL BIRDS. 



impossible to say as yet whether or not they are odontornithie. All the deposits of Cretaceous 

 age in North America, in which birds have been found, are marine, and the species appear to 

 have all been aquatic. 



26. APATORNIS CELEB. 



lehthyornis celer, Maesh, Am. Joum. Sci., v, Jan., 1873, p. 74. 



Apatornis celer, Marsh, Am. Joum. Sei., v, Feb., 1873, p. 162. — Id., iUd., v, Mar., 

 1873, p. 230. — Id., ibid., x, Nov., 1875, p. 404. — Id., Am. Nat., ix, Dec, 1875, p. 626.— 

 Id., Geol. Mag., iii, Feb., 1876, p. 50. — Woodw., Pop. Sci. Eev., Oct., 1875, p. 349. — 

 Marsh, Odont., 1880, p. 193, pll. xxviii-xxxiii. 



A bird about the size of a pigeon, from the middle Cretaceous of Western Kansas ; related 

 to lehthyornis. The two known specimens are preserved in the Yale Museum. 



27. BAPTORNIS ADVENUS. 



Baptornis advenus. Marsh, Am. Journ. Sci., xiv, July, 1877, p. 86. — Id., Joum. de 

 Zool., vi, 1877, p. 387. —Id., Odont., 1880, p. 192, figg. 37-39. 



Based upon a nearly perfect tarso-metatarsal, closely resembling the same part' of Hesper- 

 ornis, and indicating an aquatic bird about as large as a loon. From Western Kansas, in the 

 same Cretaceous beds with Odontornithes and Pteranodontia. The type, and a second speci- 

 men referred to the same species, are preserved in the Museum at Yale College. 



28. GBACIILAVUS VELOX. 



Graculavus velox. Marsh, Am. Joum. Sci., iii, May, 1872, p. 363. — Id., ibid., v. Mar., 

 1873, p. 229. —Id., Odont, 1880, p. 194. — CouES, Key, 1872, p. 349. 



A bird about two-thirds as large as a cormorant. The remains were found in the green- 

 sand of the middle marl bed, or upper Cretaceous, near Homerstown, New Jersey, and are all 

 preserved in the Museum of Yale College. 



29. GBACULAVUS PXIMILUS. 



Crraeulavus pumilus, Marsh, Am. Journ. Sci., iii, May, 1872, p. 364. — Id., ibid., v. 

 Mar., 1873, p. 229. — Id., Odont., 1880, p. 195. — Coues, Key, 1872, p. 350. 



A smaller species than the foregoing, from the same formation and locality. Remains 

 also in the Yale Museum. 



Note. Several western species, provisionally referred to the genus Cfraculamis, have since 

 been identified with lehthyornis, which see. 



30. HESPEROBNIS REGAXIS. (See p. 63, fig. 15.) 



Resperornis regalis. Marsh, Am. Journ. Sci., iii, Jan., 1872, p. 56. — Id., iUd., iii. 

 May, 1872, p. 360. —Id., ibid., x, Nov., 1875, p. 403. —Id., ibid., xiv, July, 1877, p. 85, pi. 

 V. — Id., Am. Nat., ix, Dec, 1875, p. 625.— Id., Geol. Mag., iii, Feb., 1876, p. 49, pi. ii.— 

 Id., Odont., 1880, pp. 1-117, p. 195, pU. i-xx.— CouES, Key, 1872, p. 195. — WoODVf., Pop. 

 Sci. Eev., Oct., 1875, p. 337. — Seblet, Journ. Geol. Soc, xxxii, 1876, p. 510. — Huxl., 

 Pop. Sci. Monthly, x, 1876, pp. 215-218.— Vogt, Revue Scient., xvii, 1879, p. 247.— Dana, 

 Man. Geol., 1880, pi. iv. 



Reference to p. 238, antea, will show the essential characters of the order or subclass 

 Odontolcce, of which the present species is a type. Hesperomis may be tersely characterized 

 as a gigantic diver, some six feet in length from the point of the bill to the end of the toes, 

 standing over three feet high in the position represented in the above-cited figure. While the 

 general configuration of the skeleton may be likened to that of a loon, the conformation of the 

 sternum is ratite, like that of struthious birds, and the wings are mdimentary or abortive, only 

 a remnant of a humerus being left ; other struthious characters are noted in various parts of 

 the skeleton ; the jaws are long and furnished with sharp recurved teeth implanted in grooves, 

 but the vertebrae are heterocoelous, or saddle-shaped, and the coccyx is short, as in ordinary 

 birds ; most of these characters separating this odontolcous type of Odontornithes sharply from 

 both OdontotornuB and Sav/rwr<B. Comparison of the three Mesozoic genera, Hesperornis, 



