L 



Mr. 0. Thomas on Mustek albinucha, Gray. 



371 



that belonging to the Paris Museum, the presence or absence 



tooth 



_ — _ 



premolar, there is no diastema 

 where it should stand, and its 

 absence is evidently due to the 

 shortening of the jaws and the 

 consequent strengthening of the 

 biting power of the animal. 



One species of Mustelidse, how- 

 ever, the Lyncodon patagonicus 

 of Gervais, is described as hav- 

 ing the identical number of teeth 

 ordinarily found in Pcecilogale ; 

 and I therefore wrote to Prof. 

 W. P. Gervais, of the Paris 

 Museum, asking him if he could 



As to the 



allow 



me 



to see the 



original 



and only known skull of that 

 species, and he has most kindly 

 sent it to me to examine. I 

 find, as might be expected in an 

 animal from Patagonia, that it 



has no special relationship what - 

 ever with the South African 



Pcecilogale 



although its 



dental formula is the same. The 



be seen by com- 



a U/UtH/UttLD. CllLll^Uil 11 1LO \M.VjllVClL ±KJL 111 U1CI 10 



whole shape of the skull is different, as may 

 paring Prof. Gervais's excellent figures with the woodcuts 

 now given ; the auditory bullae are not so peculiarly flattened 

 as in Pcecilogale^ being, in fact, unusually inflated ; the floor 

 of the meatus is more produced, so that the opening is closer 

 to the glenoid fossa and is not visible on viewing the skull 

 from below. Altogether it is evident that no genus which was 

 supposed to be founded on genetic affinity could contain these 

 two forms, which have independently developed a similar re- 

 duction in the number of their teeth. 



Finally, not only the colour but the plan of coloration (see 

 P. Z. S. 1864, pi. x.) is so absolutely different from that of any 

 other Mustela. that that alone would almost furnish a reason 



M. 



nucha. 



