26 The Ottawa Naturalist. [May 



breadth as measured across the zygomatic arches; its teeth, how- 

 ever, are decidedly less robust. Whilst in the wolf skull the 

 maxillary teeth (canine, premolars and molars) occupy a space 

 of 103 mm., a hke measurement in the Tranquille skull gives 

 91 mm. It is thought that the latter skull is that of a collie. 

 Mr. W. Fortune, the owjier of one of the ranches, of which there 

 are two at Tranquille, informs the writer that he has had a 

 number of Scotch collies of which several have died during the 

 past few years. 



In the wolf skull the first premolar has a small interval 

 (about 1 mm.) between it and the second premolar with a wider 

 space (about 2 mm.) separating it from the canine. Here the 

 first premolar has the same proportions as the anterior tooth 

 in the supposed collie skull, but is larger, with a similarly sloping 

 posterior edge. 



The collie shows its affinity to the wolf in its narrow skull 

 and lengthened muzzle. It would be interesting to have records 

 of the occurrence of extra teeth, in breeds of dogs having elonga- 

 ted skulls, and in the wolf if such teeth occur, as they probably 

 do, in this animal. Supernumerary upper first premolars are 

 known in the doinestic cat. 



Measurements of Skulls. 

 Length of skull, occipital condyle to anterior Dog. Wolf. 



end of premaxilla -- 210 mm. 216 mm. 



Breadth of cranium at greatest constriction 



behind the orbits 43 43 



Breadth of same at greatest expansion be- 

 low squamoso-parietal suture 65 70 



Breadth of frontals at postorbital processes. . 63.5 55.5 



Breadth of skull at alveolar border above 



second preinolar 41 42 



Breadth across zygomatic arches . 118 120 



Length of nasals. 88 87 



Length of premolar-molar series 77 88 



Antero-posterior diameter of crown of upper 



carnassial. .. ....- 20 24.5 



Anterior transverse diameter of same 10 14 



Antero-posterior diameter of crown of upper 



first premolar 6.5 8 



The upper teeth of the Tranquille skull are shown, in the 

 figure accompanying this note, three-fourths the natural size. 



The writer "is indebted to Mr. Andrew Halkett, Naturalist 

 and Curator, Fisheries Museum, Ottawa, for the loan of the skull 

 of the white wolf above mentioned. 



