1880.] PROF. FLOWER ON ICTICYON VENATICUS. 71 



received at the British Museum from the Brazils under the name of 

 Cynalicus meJa7iog aster. It may here be noticed that the reference 

 by the same author' of Canis bracJiyotus, of which the skull and 

 teeth are figured by Blainville (' Osteographie,' gen. Canis, pis. viii. & 

 xii.) to this species, is incorrect ; but Yau der Hoeven has given a good 

 figure of the same parts ^. Aery recently Cope has described (without 

 figure) an extinct species from Oregon, which he refers to this group, 

 under the name of Icticyon crassivultus^. 



In consequence of the dental formula, and some superficial re- 

 semblance in external form, this animal has often been placed by 

 systematists among the Mustelidse ; but its true position as a dog 

 has been recognized by all who have closely investigated its struc- 

 ture. The living specimen much recalled in appearance a young 

 Fox, and had the manners of a playful puppy. It was a female, 

 and at the time of death nearly adult. All the permanent teeth 

 were in place ; but the canines were not fully protruded, and the 

 epiphyses were not united to the ends of the long bones. 



The only decided character by which it has been separated 

 generically from Canis, besides the shortness and broadness of the 

 skull, is the reduction in develcnment of the true molar teeth. In 



the upper jaw the posterior molar of Canis C^) is stated to be 



absent, and -^ is smaller and simpler than in the Dogs generally. 

 In the lower jaw, whereas Canis lias usually three true molars, 

 Icticyon has but two ; and the last which is developed is con- 

 siderably smaller than its homologue in the ordinary forms. This 

 appears to have been the case in all the specimens hitherto ex- 

 amined ; but the present example presents an interesting variation, 

 as, in addition to the teeth usually described as being present, it has a 

 pair of very small tubercular molars above, the crowns of which are 

 divided into an outer and an inner cusp. The dental formula, therefore, 

 is i. -g, c. J. /»«• 4. '"•2=10^40, corresponding with that of Canis 

 primcevus of Bengal, constituting the genus Cuon of Hodgson, to 

 which animal Icticyon comes nearer, in the general form of the 

 skull, than to any other of the group. The presence of these small 

 teeth may be an individual peculiarity ; or it may be that they are 

 normally developed in the young animal, and are early deciduous, so 

 that in the older specimens previously examined they have escaped 

 notice. In any case they show a most interesting transitional cha- 

 racter, and point to the fact that, in the reduction of the molar 

 teeth, Icticyon is modified from a more generalized canine type. 

 Another slight peculiarity in the dentition is that the inner tubercle 

 of the upper sectorial is placed rather further from the anterior 

 edge of the tooth than in Canis. 



' ' Catalogue of Carnivorous, Pachydermatous, aud Edentate Mammalia in 

 the British Museum,' by J. E. Gray, 1869, p. 183. 



2 J. Van der Hoeven, " Over het geschlacht Icticyon," Verhandelingen der 

 Koniuklijke Akademie van Wetenschappen,' Derde Deel (Amsterdam, 1856). 



^ E. Cope, " On the Genera of Felidse and Canidw," Proc. Aoad. Nat. Sciences 

 Philadelphia, July 8th, 1879. 



