386 MR. R. I. POCOCK ON 



the Museum of the College of Surgeons are: — (1) that C. ant- 

 arctlcits and C latrans are not closely allied ; (2) that C.cmtarcticus 

 is more nearly related to the C. thous (^ cancrivorus) group of 

 South American Canidse than to G. latrans ; (3) that G. latrans 

 must be affiliated with such Old World species as G. j^'^Mipes, 

 G. lupaster and G. anthus, and not with C. antarcticus. The 

 first and third of these conclusions ai-e borne out by the 

 external characters of the two species concerned. My reasons 

 for these conclusions are as follows : — 



The sagittal area and sagittal crest. — As Huxley and Mivart 

 have shown, the skull of G. antarcticus has a well-marked lyiiform 

 sagittal area which, according to the evidence of available crania, 

 persisted throughout life, although in one of the three specimens 

 in the British Museum it is decidedly narrower than in the two 

 others. In the skulls of G. latixms that I have seen there is no 

 distinct lyriform sagittal area, but in adult skulls there is a 

 median cariniform sagittal crest varying in height with age. 

 Even in two young skulls, in both of which the sphenoidal and 

 occipital sutiu'es are open, while one still retains a milk canine 

 behind the permanent canine, there is no lyriform sagittal area. 

 The significance of this depends upon the fact that the young of 

 many species of Canida? of corresponding age or older show a 

 stronger or weaker lyriform area corresponding with the sinuosity 

 of the upspreading temporal muscle on each side, although in the 

 young of no species of dog in which the adult possesses a carini- 

 form sagittal crest does the lyriform sagittal area show, I believe, 

 the development and definition it exhibits in the adult of 

 G. antarcticus. However that may be, if G. antarcticus and 

 G. latrans were closely related, we should at least expect to see 

 a well-defined lyriform sagittal area in the skulls of subadult 

 individuals of G. latrans killed before the temporal muscles had 

 reached the summit of the cranium. But, as has been said, this 

 area is remarkable for its indistinctness in immature skulls of 

 that species. 



The occipital crest. — In G. antarcticus the occipital crest, when 

 viewed from above, is transversely truncated and not angular ; 

 when viewed from the side it only overhangs the vertical portion 

 of the supraoccipital to a small extent ; and when viewed from 

 behind it forms a truncated angle. In G. latrans this crest is 

 angularly produced backwards in the middle line, overhangs the 

 occipital area to a much greater extent, and is more acutely 

 anoled from behind. It varies in shape and development in this 

 species, but never, so far as I have seen, resembles that of 

 G. antarcticus (text-figs, 70 & 71). 



The malar hone. — In Ganis antarcticus the anterior portion of 

 the malar bone is marked by a strong masseteric ridge traversing 

 appi'oximately the middle of its outer surface; the inferior edge 

 of the bone close to the maxilla is expanded convexly to afford 

 additional support to the masseter muscle ; its ujDper edge close to 

 the maxilla is somewhat out-turned, forming a very appreciable 

 hollow on the subjacent portion of the maxilla above the fii'st 



