6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 87 



below the fossil horse horizon. The specimen comprises about one 

 third of the bone. 



The type specimen of this cormorant is the proximal end of a 

 right metacarpal, including about one half the bone, preserved with 

 other material in the Marsh collection in the Peabody Museum at 

 Yale University. Through the kindness of Dr. Malcolm R. Thorpe, 

 an excellent cast of this type has been available for study, which has 

 made possible proper consideration of its characters and relationships. 

 In general, this type is similar to the metacarpal in modern Fhalacro- 

 corax auritiis but is decidedly larger, being larger, in fact, than any 

 living cormorant. It is about equivalent in size to the extinct Pallas's 

 cormorant, Fhalacrocorax pcrspicillutits, from Bering Island, differing 

 from this species in being more slenderly, less heavily, molded. 



The fragmentary ulna here under discussion is distinctly larger 

 than that of living cormorants, though not quite as heavy as in P. 

 perspicillatus. On this basis of relative proportion it is identified as 

 P. idahensis. Its characters in general, aside from dimensions, are 

 those of other cormorants, except that the carpal ridge is somewhat 

 longer. This find represents the second known occurrence of this 

 species. 



In the original description Marsh states that his type of idahensis 

 " is from a fresh-water Tertiary deposit, probably of Pliocene age, 

 on Castle Creek, Idaho Territory ". Dr. O. P. Hay ' places this 

 locality in the Pleistocene, stating in the last reference given that it 

 is from the Nebraskan stage. On this basis P. idahensis was listed as 

 from the Pleistocene in the third and fourth editions of the " Check- 

 list of North American Birds " prepared l)y committees of the Ameri- 

 can Ornithologists' Union. Dr. Plarold T. Stearns, of the United 

 States Geological Survey, who has done extensive work on the geology 

 of this general area, informs me, however, in recent correspondence 

 that the deposits at Castle Creek are correlative with the Hagerman 

 beds or possibly older. This would place them in the Pliocene, so that 

 Phalacrocorax idahensis should be allocated to the Pliocene, instead 

 of to the Pleistocene as generally accepted at present. 



PHALACROCORAX AURITUS (Lesson) 



Carbo auritus Lesson, Traite d'Orn., Livr. 8, June 11, 1831, p. 605. 



A right metatarsus (U.S.N.M. no. 12239), complete except for 

 slight wear on the margins of its various processes, was obtained in 



* Bull. U. S. Geol. Surv. 179, 1901, p. 533; and Carnegie Inst. Washington, 

 Publ. y22, 1923, p. 8. 



