CANIS. 25 
(4) The length of the upper carnassial pm. 41s superior or at least equal to 
that of the molars m. 1 and 2 in wolves, while in dogs the length of pm. 4+ is less 
than, or at most equal to, that of the m. 1 and 2 (Gaudry and Boule). 
(5) The plane of the eye-socket is more obliquely inclined to the brow, 7. e. the 
orbito-frontal angle is less in wolves than in dogs (Studer) (see Text-fig. 8). 
(6) The brow is more swollen at the base of the muzzle in dogs (de 
Blainville). 
(7) The zygomatic arch is less curved and shorter in the wolf (Vieira). 
(8) The coronoid process reaches above the zygomatic arch in the dog but not 
in the wolf (Vieira). 
(9) The caudal vertebra are more variable in the dog (de Blainville). 
Denny' also refers to the following points: (a) The intermaxillaries (? nasal 
Text-ria. 8.— Anterior view of the skull of a dog, and instrument for measuring the orbito-frontal angle. 
processes of the premaxille) and nasals are longer and narrower in dogs than in 
wolves; (b) the nasal cavity is wider in wolves; (c) the orbital projections 
(probably the post-orbital processes of the frontals) are more acute in dogs; () the 
jaws are wider ; and (e) the tympanics are larger in wolves. 
The above is a considerable list, but the great majority of the pomts amount to 
very little and are quite inconstant and unreliable. 
Probably the most important character is No. 5, for which we are indebted to 
Studer.2 The angle to which he alludes can be better realised by the preceding 
diagram (Text-fig. 8) than by description. He regards as belonging to wolves, 
skulls in which the angle between the plane of the orbit and that of the brow 
measures 40—45°, and as belonging to dogs, skulls in which the angle is greater 
1 «Proc. Yorks. Geol. Polyt. Soc.,’ 11, 1857 (1859), p. 538. 
2 «Abh. schweiz. pal. Ges.,’ xxvii, p. 13. 
