174 FIELD MUSEUM or NATURAL HISTORY ZOOLOGY, VOL. X. 



and relatively heavier dentition with the last upper molar particularly 

 large and the whole toothrow in consequence more crowded. 



Measurements of the skull and teeth are as follows : Occipito-nasal 

 length 137.5; basal length 144.8; basilar length 136; basion to spheno- 

 ideum 37.4 (44) ;* sphenoideum to gnathion 102(112); zygomatic breadth 

 82.3 (91); breadth across postorbital processes 37; interorbital con- 

 striction 26.7; breadth of braincase 49.5 (51); length of nasals 54 (62); 

 length of palate 77.3 (82); length of Pm. 1 4.6 (4); Pm. 2 9 (8); Pm. 3 10.7 

 (10); length and breadth Pm. 4 17.7 x 8.3 (15 x 7); M. 1 10.6 x 14.5 (10 x 

 i4);M. 2 6.sx 10.1 (5.5 x 6.5); length of Pm.! 4.4 ( 4 );Pm. 2 9.3 (8);Pm. 3 

 10 (10); Pm.4 10.9 (n); length and breadth M.! 17 x 7 (16 x 7); M. 2 

 8 x 5.7 (8x4); M. 3 3.9 x 3.3 (3 x 3). 



For the present, I have retained this species and closely allied forms 

 in the genus Canis, feeling that this course is desirable until such time 

 as an exhaustive phylogenetic study of all the South American canids 

 is made. An able contribution to this subject has been made recently 

 by Pocockf who points out certain cranial and dental characters dis- 

 tinguishing Canis antarcticus from Canis latrans.% He also demonstrates 

 a degree of similarity between Canis antarcticus and C. thous. The 

 thous group, however, shows similarity to Urocyon, and speaking gen- 

 erally it might be said that true Canis and Urocyon are at opposite ends 

 of a series in which species like C. antarcticus and C. thous form the 

 intermediate steps. In this series C. antarcticus unquestionably falls 

 nearer to true Canis than to Urocyon. Just where generic and sub- 

 generic divisions should be made, therefore, depends upon more thor- 

 ough investigation than has yet been made. 



* Measurements in parentheses are those of the type of C. magellanicus published 

 by Mivart (Monogr. Canidae, pp. 55-56, 1890). 



t Proc. Zool. Soc. Lond., pp. 382-393, 1913. 



I Much larger series of the latrans group than were available to Pocock bear out 

 his general observations, although occasional skulls show a slightly developed 

 parietal shield quite equal to the condition in certain species of " Cerdocyon." 



While the above is in press, the current (March) number of the Annals and 

 Magazine of Natural History comes to hand with its important discussion of the 

 names of South American Canidae by Thomas. It is regrettable from the standpoint 

 of those less fortunately situated, that one so eminently competent and so favored 

 with material should not have characterized the various groups otherwise than 

 nomenclaturally, for at least part of them have not been defined zoologically. 



The Peruvian specimen mentioned above is doubtless referable to Pseudalopex 

 culpcEus andina of Thomas, described as slightly different in color from P. c. reissi 

 of Ecuador and probably also of that part of Peru in which our work was done. 

 P. c. magellanicus is recognized as a third subspecies and P. lycoides of Tierra del 

 Fuego is given specific rank. 



