60 SYSTEMATIC PALEONTOLOGY 



inferior (outer) narrower articular margin is much narrower than in 

 S. bassana. 



Length to inner distal angle 2.02 in. (50 mm.) 



Length to posterior basis of scapular arti- 

 culation 78 in. (1.56 mm.) 



Width of head last point 57 in. (1.14 mm.) 



Width of glenoid cavity 25 in. (.50 mm.) 



Width of shaft 23 in. (.46 mm.) 



Width of distal extremity to middle line 



of shaft produced 43 in. (86 mm.) 



Thickness distal extremity 38 in. (76 mm.) 



" This gannett was somewhat smaller than the S. bassana of our 

 northern coasts, and approached more nearly those of the tropical 

 seas/' 



Occurrence. — Calvert (possibly Choptank) Formation. Calvert 

 Cliffs. 



Collection. — American Museum of Natural History. 



Order TUBINARES. 

 Family PROCELLARIDAE (Shearwaters). 



Genus PUFFINUS Briss. 



PuFFiNus coNRADi Marsh. 

 Plate XXVI, Figs. 3, 4. 



Puffinus conradi Marsh, 1870, Amer. Jour. Sci., ser. ii, voL xlix, pp. 213, 213. 



Description. — " The collection of the Academy of Natural Sciences 

 in Philadelphia has for many years contained the distal half of a left 

 humerus, and the lower portion of a right ulna, of an aquatic bird, 

 which were discovered in the Miocene of Maryland by T. A. Conrad, Esq. 

 A brief mention of these specimens, and of some other ornithic remains 

 from the United States, has already been made by Professor Leidy,' but 

 no description of them has yet been published. The specimens are 



iProc. Acad. Nat. Sci. Phila, vol. xviii, 1866, p. 237. 



