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me for investigation. The specimens consist of jaw-fragments of a large 

 wolf and tiger. 



Professor E. 0. Hovey writes me that they are part of a collection of fossil- 

 bones which were obtained from a wash in the side of a hill about twenty- 

 five miles inland from San Leandro, California. 



The fossils are not petrified, and indeed have undergone almost no altera- 

 tion, and are probably quaternary. 



The fossil pertaining to a tiger consists of an upper-jaw fragment, repre- 

 sented in Fig. 3, Plate XXXI, one half size. It contains the second pre- 

 molar, and retains the alveolus of the one in advance and that of the canine. 



The specimen indicates a species as large as the largest living Bengal tiger, 

 and, indeed, is slightly larger than the corresponding part of the largest spec- 

 imen of a skull among many in the Academy Museum of Philadelphia. 



The proportions of the specimen indicate a larger animal than the extinct 

 Fells augustus, as represented by the fossil-fragments from the Niobrara 

 River of Nebraska. They also indicate an animal as much smaller than the 

 extinct F atrox, as represented by the ramus of a lower jaw found in associ- 

 ation with remains of the Mastodon americanus and Megahnyx Jeffersoni, 

 near Natchez, Mississippi, as the Bengal tiger is compared with the latter. 



Taking into consideration the extent of variation in size of the same 

 species, there can be no question that the California fossil might pertain to 

 either the Fells augustus or the F. atrox. Its associations might aid in the 

 determination whether it was either of these, or whether it is distinct. If 

 found in association with remains of Mastodon americanus, it might reason- 

 ably be supposed to pertain to a smaller individual of Fells atrox ; if with 

 any of the peculiar species of the Niobrara fauna, it might be supposed to be 

 a larger individual of F. augustus. 



Comparative measurements of the fossil with the corresponding portion of 

 the skull of a large Bengal tiger from Hindostan are as follows: 



Space occupied by the upper premolars and canine. 

 From back of last premolar to canine alveolus 



Antero-posterior diameter of second premolar 



Diameter of canine alveolus 



