October 24, 1902.] 



SCIENCE. 



676 



teeth truncate posteriorly, which certainly do 

 not belong with Deinodon; (4) that he subse- 

 quently selected the two latter (2 and 3) as the 

 types of Aublysodon. The Cretaceous carniv- 

 orous dinosaur of the Judith River beds 

 should, therefore, be named Deinodon. Be- 

 longiug to this is the tjTJe species D. horridus 

 Leidy; probably also the species D. cristatus 

 Cope aud D. IcBvifrons Cope, from Montana. 

 To Dryptosaarus, on the other hand, may well 

 belong the large Upper Cretaceous carnivore 

 D. incrassatus Cope, from the Edmonton 

 series of Alberta. 



The discovery of additional remains of Orni- 

 thomimus in the Belly Eiver series, as repre- 

 sented by a large new species, is of great in- 

 terest. Mr. Hatcher states that he found 

 Marsh's typt of this genus, consisting of a foot 

 and a portion of a limb, on Cow Island, Mis- 

 souri River, at a level which he estimates from 

 1,500 to 1,600 feet below the summit of the 

 Judith Eiver beds, and 500 to 600 feet below 

 the level of Marsh's type of Ceratops mon- 

 tamLS. 



Ornithomimus alius is probably a successor 

 of a comparatively small and lightly built 

 dinosaur recently discovered by the American 

 Museum parties in the Como Beds of Wy- 

 oming.* Ornithomimus is more progressive 

 than its supposed ancestor, in the development 

 of cursorial rather than prehensile phalanges 

 in the pes, these elements having nearly lost 

 the recurved megalosauroid structure. 



One. of the distinguishing features of the 

 Belly River fauna is the great number and va- 

 riety of the Iguanodonts. The separation of 

 Mid- from Upper Cretaceous iguanodonts, 

 will, if confirmed by closer examination and 

 determination of geological horizons and levels, 

 greatly increase our understanding of this 

 moat interesting group. Without professing 

 to have made an adequate investigation, Pro- 

 fessor Osborn is strongly of the opinion that 

 the Cretaceous includes a number of distinct 

 genera, representing a wide adaptive radiation 

 and probably a number of successive phyla. 

 The wide differences in the mode of succession, 

 general shape and border sculpturing of the 



* It will .shortly be described in a bulletin of the 

 American Museum. 



teeth, indicate profound changes which re- 

 quired an enormous period of time for their 

 development. There are also indications of 

 a separation of the Iguanodonts into light- 

 and heavy-limbed series, smaller and larger, 

 swifter and clumsier, of great variety in tooth 

 structure. 



In the Belly River series we find the new 

 species Trachodon selwyni Lambe, an animal 

 nearly double the size of the Iguanodon man- 

 telli of the English Wealdon (Upper Jurassic). 

 A more delicately built iguanodont P. margin- 

 atus Lambe resembles the less robust iguano- 

 dont Pteropelyx grallipes Cope, but is specifi- 

 cally distinct in the border sculpture of the 

 teeth. A third new species, or even genus P. 

 (Didanodon) altidens Lambe, is distinguished 

 by exceptionally high narrow teeth. 



In the order Ceratopsia, perhaps more than 

 in any other, the resemblance between the 

 Belly River and Montana stages and the con- 

 trast between these and the Wyoming Laramie 

 stages, so far as known, are distinctly marked.. 

 In general the contrast in the Ceratopsia is as 

 follows: Belly and Judith Eiver Ceratopsia, 

 of smaller size; nasal horns very large; small 

 frontal or supraorbital horns; widely open 

 supratemporal f ossse ; teeth single ( ? Mono- 

 clonius) and double fanged. Laramie Upper 

 Cretaceous, Ceratopsia, of larger size; na- 

 sal horns relatively smaller (Triceratops) or 

 even vestigial; greatly developed frontal 

 horns; supratemporal fossae open (Torosaurus) 

 or nearly closed (Triceratops). 



Monoclonius Cope is the first name applied 

 to a Montana ceratopsid. The apparently new 

 species, M. dawsoni, M. canadensis and M. 

 hclli, discovered by Mr. Lambe in the Belly 

 River series, add to the variations in the 

 Monoclonius type of skull in the Mid-Cretace- 

 ous. It will be observed that all of these 

 species are known to possess large nasal and 

 small supraorbital horns. This stage of horn 

 evolution may be contemporaneous with and 

 independent of that in the southern Laramie 

 dinosaurs, in which the nasal horns are invari- 

 ably smaller than the frontal horns, but 

 coupled with the smaller size and open tempo- 

 ral fossae, it would appear to be more primi- 

 tive. The new genus Stegoceras, proposed in 



