24 STUDIES IN TASMANIAN MAMMALS, LIVING AND EXTINCT, 



32050) is identical with the jaws of Zygomaturus, Owen's 

 determination of Notoiherium as a genus stands good, 

 and De Vis' dissensions rule out. At the same time, the 

 evidence to date of writing tends to show that the real 

 position is this : — 



1. That the mandible from the Boyd's Collection, of 

 which we hold an accurate cast, came from a 

 male animal, and that the first Zygomaturus 

 skul! (and, therefore, Owen's, cast, Brit. Mus. 

 Coll. 33259) was a female. 



2 Owen's so-called "female" jaws, we will deal with 

 later, just recalling as we pass along that Owen 

 made this determination with a strong reserva- 

 tion, and published his note with a query ap- 

 pended to it. 



3. That De Vis afterwards obtained male skulls of 



his so-called "Zygomaturus " which depart — in 

 sex variation — rather strongly from those of the 

 female, and that in the circumstances the posi- 

 tion he took up is readily understood. In eoing 

 over this matter it is also evident that De Vis' 

 contentions did good work, and are even now as- 

 sisting to solve the problem of these ancient giant 

 marsupials. 



4. If the Bovd's collection mandible is placed side 



bv side with the mandible of the latest dis- 

 covery from Smithtcn, thev will be found to 

 aisrree in toto, while the skull itself agrees ex- 

 actlv with De Vis' determination of Zygomaturus, 

 and departs from Owen's cast in exactly the 

 way De Vis claimed. 



5. Being practically certain (evidence yet to be 



given) that our animal was a male, the sex dif- 

 ferences square all other outstanding points be- 

 tween Owen and De Vis — and Zygomaturus, as 

 reconstructed by the latter, becomes a sex varia- 

 tion, and not a taxonomic one. 



SECTION 2. 



TPIZ OSTEOLOGY OF THE CERVICAL VERTEBRA. 



As we duly point out in our published < 19 ) introduc- 

 tory note, the cervical vertebras of Nototherium mitchelli 

 are of special morphological interest, combining in fact 



