1900.] 



STRUCTURE OF THE MUSK-OX. 



707 



and inaxillse is characteristic 1 and wavy, because each palatine has a 

 median and a lateral lobe extending forward on both sides of the 

 foramina ' palatina (fig. 7). The molar series are a little arcuate 

 and converge anteriorly, so that, for instance, in an adult bull 

 the distance between them is anteriorly 56 and posteriorly 84 mm., 

 measured at the alveolar brim. The length of the molar series in 

 the same specimen is 144 mm. The length of the molar series 

 compared with the basal length of the skull is in a cow 32 per cent, 

 and in a bull 31 per cent, of the latter measurement \ The palate 

 extends well backwards so that the ehoanse open behind a line 

 connecting the posterior edge of the last molars. This seems to 

 be a difference from the condition of the Caprina as well as that of 



Fig. 7. 



Palatal surface of skull of Musk-ox. 



many Antelopes (Kemorhcedus, Rupicapra, Gazella, Antilope 2 , 

 Cephalophus, &c). On the other hand, it offers a superficial re- 

 semblance to the Bovina. 



The extension of the masseter muscle in a forward direction 

 over the lateral surface of the maxillary is comparatively short, 

 probably because it has such a wide area on which it may expand, 

 below the orbital tube (fig. 3, p. 691). As a result of this, the crista 



1 This relation between the length of the molar series and the basal length 

 of the head seems to be pretty equal in the ruminants. The following results 

 may be quoted to prove this : in a Buffalo the molar series measured 3O0 p. c. 

 of the basal length of the skull, in a common Ox 293 p. c., in a Goat 31'] p. c, 

 in Nemorhceduii 32 - 3 p. c, in Rupncapra 29'7 p. c, in Gazella 34 - l p. c, in 

 Antilope 310 p. c, in Cephalophus 333 p. c, in the Wapiti 22 - 8 p. c, in the 

 Reindeer 279 p. c. ; but in Saiga, with its reduced number of teeth, not less thau 

 29 8 p. c, and so on. 



2 In the Saiga the choanse open behind the molars, a fact which may 

 stand in relation to the reduced number of molars. 



