826 SYSTEMATIC SYNOPSIS OF FOSSIL BIBBS. 



impossible to say as yet whether or not tlioy are odontornithic. 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. APATOKNIS CELER. 



Iclithyorim celer, Marsh, Am. Journ. Sci., v, Jan., 1873, p. 7i. 



AxMtovnis celer, Maksh, Am. Journ. Sci., v, Feb., 1873, p. 162. — Id., ibid., \, Mar., 

 1873, p. 230. — Id., ihid., x, Nov., 1875, p. 104. — Id., Am. Nat., ix, Dec, 1875, p. 626.— 

 Id., Geol. Mag., iii, Feb., 1870, p. 50. — Woodw., Pop. Sci. Rev., Oct., 1875, p. 349.— 

 Maiish, Odont., 1880, p. 192, pll. xxviii-xxxiii. 



A liird about the size of a pigeon, from the middle Cretaceous of AVestern Kansas ; related 

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



27. BAPTORNIS ADVENUS. 



Sapiuriiis (iilrenus, Marsh, Am. Journ. Sci., xiv, July, 1877, p. 86. — Id., Journ. 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. GRACULAVUS VELOX. 



Graculaviis velox, Marsh, Am. Journ. Sci., iii. May, 1872, p. 363. — Id., ihid., v, Mar., 

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



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

 sand of tlie middle marl bed, or upper Cretace<.ius, near Hornerstown, New Jersey, and are all 

 preserved in the Museum of Yale College. 



29. GRACULAVUS PUMII^US. 



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

 Mar., 1873, p. 229. — Id., Odont., 1880, p. 195. — Coues, Key, 1873, 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 G-racidaviis, have since 

 been identified with Ichtliyornis, which see. 



30. HESPERORNIS REGALIS. (See p. 63, fig. 15.) 



Hesperornifi regcdis, Marsh, Am. Jouru. Sci., iii, Jan., 1872, p. 56. — Id., ibid., iii. 

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

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

 Id., Odont., 1880, pp. 1-117, p. 195, pll. i-xx.— Coues, Key, 1872, p. 195. — Woodw., Pop. 

 Sci. Rev., Oct., 1875, p. 337. — Seei.ey, Journ. Geo! Soc, xxxii, 1876, p. 510.— Huxl.,. 

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

 Jlan. Ge(d., ISSO, pi. iv. 



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

 Odonfolca, of which the present species is a type. Hesperornis 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 fiver 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 ratife, like that of struthious birds, and the wings are rudimentary or abortive, only 

 a remnant of a liumerus being left ; other struthious characters are noted in variou.s parts of 

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

 lint the vertebra? are heteroccelous, or saddle-shaped, and the coccyx is short, as in ordinary 

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

 both OdontotormcE and Saururce. Comparison of the three Mesozoic genera, HesperorDia. 



