254 NATURAL SCIENCE. Oct., 



in a thigh bone which is much more Hke that of an Emu or a 

 Cassowary than that of a Moa. " There is thus no longer any reason 

 for supposing a late migration of Struthious birds between New 

 Zealand and Australia." At the same time {Proc. Linn. Soc. N. S. 

 Wales [2] , vol. viii., pp. 7-10) Mr. De Vis discusses a second Queens- 

 land fossil — the upper jaw of Owen's great extinct wombat, Phasco- 

 lomis — and points out how another guess has been exploded. Some 

 have supposed that the huge broad chisel-like teeth named Scepar- 

 nodon by Owen were the upper incisors of this animal, but Mr. De 

 Vis's discovery now disproves the supposition. Phascolonus has very 

 stout upper incisors, and the animal to which the broad chisel-like 

 teeth belong is as mysterious as ever. It is a distinct advantage to 

 have accurate descriptions and figures of fragmentary fossils, and it 

 is often desirable to assign to them provisional names ; but literature 

 is already sufficiently burdened, and may well be spared the 

 additional incubus of elaborate guesswork and prosy prophecy. 



In reference to general principles touched by this kind of 

 Palaeontology, we desire to add a word of warning to students who 

 come across Professor H. G. Seeley's note on a supposed reptilian 

 tooth with bifurcated root in the last number of the Ann. and Mag. Nat. 

 Hist. (ser. 6, vol. xii., p. 227). It is a generally accepted principle 

 that the teeth of reptiles are distinguished from those of mammals by 

 having invariably a simple — not bifurcated — root. There is, it is 

 true, not much difference between the longitudinally grooved root of 

 certain reptiles and the double-rooted premolars of typical mammals ; 

 but there is no certain exception to the rule as yet on record. Now 

 Professor Seeley describes what he terms an abnormal tooth of 

 Ntithetes, an extinct reptile from the Purbeck formation ; and if the 

 determination be correct, the discovery is of great interest. We 

 must, however, point out that there is no evidence whatever that the 

 tooth described does belong to Nuthetes or to any other reptile ; it was 

 found isolated, and in a deposit where mammalian remains occur. 

 Moreover, it appears to us much like the upper canine tooth (with 

 bifurcated root) of the little insectivorous mammal Triconodon found at 

 the same place. There is thus so much uncertainty in this determina- 

 tion that the good old law remains unaffected, and we only regret 

 that such comparatively worthless fragments should add further to 

 the literature of palaeontological guesses. 



In the same paper Professor Seeley incorporates an interesting 

 observation which could not be suspected to occur under the published 

 title, and we therefore extract it. He remarks how the little Purbeck 

 reptiles, Nuthetes and Echinodon, seem to be dwarfed representatives 

 respectively of the Megalosaurian (carnivorous) and Stegosaurian 

 (herbivorous) Dinosaurs — animals which in other formations are 

 many feet in length. Sir Richard Owen long ago pointed out how 



