APPENDIX. 197 



The above named skeleton, the only one known with certainty to 

 belong to the present species, is deposited in the Yale College Museum. 



Hesperornis gracilis, Marsh. 



Marsh, American Journal Science, Vol. XI, p. 510, June, 1876. 

 This Yolume, p. 99. 



The specimen on which this species was based (number 1473) was 

 found in April, 1876, by Mr. G. P. Cooper. A nearly complete skeleton 

 (number 1679) was found in 1879, by Mr. E. W. Guild. Both specimens 

 are from the yellow chalk, near the Smoky Hill River, in western Kansas. 



The known remains of this species are in the Museum of Yale College. 



ICHTHYORNIS, 6 Marsh, 1872. 



Ichthyornis dispar, Marsh. 



(Plates XXI-XXVI.) 



Marsh, American Journal Science, Vol. IV, p. 344, Oct., 1872 ; VoL V, p. 161, Feh., 

 1873 ; Vol. V, p. 230, March, 1873. 



American Naturalist, Vol. IX, p. 625, Dec, 1875. 



Geological Magazine, Vol. Ill, p. 49, 1876. 



Journal de Zoologie, Tome IV, p. 494, Plate XV, 1875 ; VI, p. 385, ]877. 



Colonosaurus Mudgei, American Journal Science, Vol. IV, p. 406, Nov., 1872. 

 Coues, Key to North American Birds, p. 350, 1872. 



Owen, Journal Geological Society of London, Vol. XXIX, p. 520, 1873. 

 "Woodward, Popular Science Review, Oct., 1875, p. 348. 

 Huxley, New York Lectures, Popular Science Monthly, 1S76, Vol. X, pp. 215-218. 



American Addresses, p. 54-56, London, 1877. 



The type specimen of this species (number 1450) was found in 1872 

 by Professor B. F. Mudge, near the Solomon Eiver, in northwestern 

 Kansas. The bones secured are represented in the restoration of this 

 species, Plate XXVI. Eight other specimens were obtained during the 

 explorations earned on by the writer in the same region. All are from 

 the " Pteranodon beds " of the middle Cretaceous. 



All the remains of this species at present known are in the Museum 

 of Yale College. 



Iclitlivornis agilis, Marsh. 



Graculavus agilis, Marsh. — American Journal Science, Vol. V, p. 230, March, 1873. 



The type of this species (number 1209) was found by the writer in 

 October, 1872, on Butte Creek, a tributary of the Smoky Hill River, in 

 western Kansas. The locality was in the yellow chalk, of the middle 

 Cretaceous. 



These remains are in the Museum of Yale College. 



8 iX$vS, a fish, and opvii, a bird. 



