384 MR. R. I. POCOCK ON 



series of gradations of cranial and dental structure 

 between Canis latrans and C. antarcticus on the one 

 hand, and C. latrans and C. occideutalis on the other. 



I may further remark that I can discern no 



difference of the slightest importance between skulls of 

 C. latrans and those of some of our domestic dogs 

 (pp. 272-273). 



(5) In the genus Canis we have as a lowest section the 



species of the G. cancrworibs and G. vetulus type (an- 

 swering pretty much to the Aguarra dogs of Hamilton 

 Smith), the Sacaline section (C. aitreus, G. anthtis, 

 C. mesomelas, G. antarctictbs, G. latrans), and the Lupine 

 section {G. lapus and all its varieties) (p. 286). 

 Whether these paragraphs justify Mr. Lydekker's statement * 

 that G, antarcticus differs markedly from all the Canidje of the 

 mainland of South America and is appai'ently closely allied to 

 G. latrans, and Dr. Scharff's extension of this to the effect that 

 G. antarcticus is certainly closely related to G. latrans, must be 

 left to individual judgment. 



Paragraph 1 merely points out one resemblance between 

 G. antarcticus and some jackals. Paragraph 2 similarly points 

 out one resemblance between the two species, but contains no 

 suggestion of affinity between them. Paragraph 3 may be 

 interpreted as suggesting affiliation between the extreme forms 

 of South American Canidfe represented by G. vetulus and 

 G. jubatus, with G. ayitarcticus lying midway between them. 

 Paragraph 4 is more precise and states that there is no im- 

 portant structiiral break between G. antarcticus and G. latrans, 

 and that the latter similarly intergiades with G. occidsntalis 

 and G. familiaris. Paragraph 5, on the contrary, definitely 

 associates G. antarcticus and G. lat^rcns, and at the same time 

 severs the former from the group typified by G. vetuhcs and the 

 latter from the group typified by G. hqnis or occidentalis, an 

 arrangement not easy to reconcile with the views expressed by 

 pai'agraphs 3 and 4. 



After reading Prof. Huxley's paper rather carefully for 

 enlightenment on this subject, I must confess that I cannot 

 form any clear idea as to his views of the affinities of the species 

 he discussed, except in a broad sense. 



If the substance of paragraphs 4 and 5 afford some justifi- 

 cation for Mr. Lydekker's declaration respecting the relationship 

 between G. antarcticus and G. latrans, it must be admitted that 

 paragraph 3 does not support the contention that G. antarcticus 

 is quite unrelated to the species of Canidse inhabiting the South 

 American mainland. However that may be, the conclusions 

 forced upon me by the examination of five crania of G. ant- 

 arcticus and twelve of G. latrans f in the British Museum and 



* In tLe article in 'Tie Field' (Oct. 1, 1904), above referred to, Mr. Lydelsker 

 evinces less assvirance on these points; but lie evidently could not bring himself to 

 reject the authority of Huxley's opinion. 



t I use this term in its old-fashioned and broad sense, disregarding the species or 

 subspecies recently dismeuiliered from C. latrans b}- American systematists. 



