362 DR. H. GADOW ON THE SYSTEMATIC [May 3, 



With regard to the investigation of the affinities of Notoryctes, I 

 trust that a word of warning will not be taken amiss. It concerns 

 the danger which may result from the frequent habit of selecting the 

 taxonomic characters from the skeleton only, to the exclusion of 

 other organic systems. In case of fossils this cannot be helped, and 

 we have then no further means of testing the validity of our con- 

 clusions. Now, supposing only the skeleton of Notoryctes were 

 known, while the teeth and soft parts and the land where it was 

 found were unknown ; or let us suppose, for argument's sake, that it 

 " came from America," neither an impossible nor an even improbable 

 assumption. In this case many a zoologist, provided he knew his 

 osteology well, would conclude that the skeleton in question 

 belonged to a small, burrowing mammal, which was closely allied to 

 the DasypodidcB, especially to Tatusia, in fact that it was an 

 Edentate. This conclusion would be based upon the following 

 striking characters : — 



1. Anchylosis of the second to sixth cervical vertebrae. In Ta- 



tusia peba anchylosis of vertebrae 2, 3, and 4. 



2. The extraordinary strength of the first thoracic rib. 



3. The acromial process of the scapula is very long and curved, 



and has a facet on its inner surface for the upper end of 

 the humerus. 



4. There is a second spine on the postscapular fossa ; both spines 



enclosing a deep groove. 



5. The clavicles are complete and are attached to the manubrium 



sterni by the intervention of a ligament of some length. Cf. 

 Choloepus, &c. 



6. The fibula has a large foramen near the proximal portion of 



its shaft {cf. Stirling, p. 179, and fig. 7, pi. viii.). Such a 

 foramen is also present in the Cambridge specimen of 

 Tatusia peba. 



7. There is a large sesamoid bone on the plantar side of the foot. 



8. As many as six vertebrae are anchylosed with the pelvis. 



9. The caudal vertebrae possess movable chevron bones. 



10. The type of the fore and hind limbs is decidedly fossorial. 



"We might go even further and insist upon some characters in 

 which Notoryctes differs from all or from most Marsupials : — 



1. The well-developed patella. Cf. Perameles. 



2. The anchylosis of cervical vertebrae. 



3. The great strength of first thoracic rib. 



4. The possession of six sacral vertebrae, instead of 2, 3, 4, or 5, 



as Phascolomys platyrhinus. 



5. The fusion of the cuboid with the ectocuneiform bone. Unique. 



6. The decidedly fossorial type of the limbs. 



7. The apparent absence of marsupial bones ; for these, while 



scarcely visible without a lens, and not overlooked by the 

 careful describer of the first entire specimen, would certainly 

 be lost in a naturally bleached skeleton. 



