NATURAL SCIENCES OF PHILADELPHIA. 67 



One of the collections, received from the Smithsonian Institution, and ob- 

 tained by Clarence King during the U. S. Geological Exploration of the 40th 

 parallel, consists of specimens found on Sinker Creek, Idaho. These indicate 

 a later tertiary formation like that of the Niobrara River. Among them are 

 fragments of jaws and teeth of Mastodon mirijicus and of Equus excelsus, both of 

 which belong to the Niobrara pliocene fauna. 



A second collection, accompanying the former, consists of specimens ob- 

 tained by Mr. King in Utah. Among them are remains of Protohipput perdittu 

 Merychippus miralnlis, and Cosoryx, all of which belong to the Niobri ene! 



A third collection, received from Prof. II. S. Osborn, of Lafayi tti I ollege 

 Easton, Pa , was obtained on John Day's River, Oregon. The fossils indicate 

 a miocene fauna and formation like that of the Mauvaises Terres of White 

 River, Dakota. Among them are remains of Oreodon Culbertioni, and what is 

 suspected to be Stylemys Nebrascensis. 



A fourth collection, received yesterday from the Smithsonian Institution 

 was obtained by the Rev. Thomas Condon, of Dalles City, Oregon, from the 

 same locality as the latter. It consists of a few specimens, mostly uncharac- 

 teristic fragments, but among them are recognized several which pertain to 

 species of the miocene fauna of the Mauvaises Terres. Small fragments of 

 jaws with portions of molars belong to Oreodon Culbertsoni, though two exhibit 

 slight peculiarities. In an upper molar of one, a small accessory fold projects 

 from the outer concavity of the posterointernal lobe, as in the Deer. In an- 

 other specimen the inner surface of the outer lobe of part of a molar is longi- 

 tudinally rugose. In a third specimen there is no peculiarity. Another small 

 fragment of an upper jaw, with portion of a molar, apparently belongs to 

 Agriochcerus lalifrons. The specimens indicated are labelled "John Day';, 

 Oregon." 



Accompanying the last collection there is a portion of the head of a tibia, 

 about the size and form of the corresponding part in a Horse, thoroughly 

 petrified, and marked " Alkali Flats, Oregon." A few additional but un- 

 characteristic fragments are marked " Crooked R. D." 



Prof. Leidy further made some remarks on Hadrosaurus and its allies, as 

 follows : In the " Synopsis of the Extinct Batrachia and Reptilia," published 

 August, 1869, Prof. Cope has referred the supposed dinosaur Thespesius to 

 Hadrosaurus, apparently from my not having expressed the distinctive charac- 

 ters of the two genera with sufficient clearness. 



Specimens of teeth of a herbivorous dinosaur, obtained by Dr. Hayden on 

 the Judith River, a tributary of the Upper Missouri, I referred to a relative of 

 the Iguanodon with the name of Trachodon (Pr. A.N. S. 1856, 72; Trans. Am. 

 Phil. Soc. 1859, xi, 140). 



At the same time several vertebra, together with an ungual phalanx, col- 

 lected on Grand River, were referred to a geuus with the name of Thespesiui 

 (Pr. 1856, 311 ; Trans. Am. Phil. Soc. 1859, xi, 151). 



Subsequently the great part of the skeleton of an Iguanodon-Wke animal was 

 discovered in the green sand formation of New Jersey, and described by me 

 under the name of Hadrosaurus (P 'r. 1858, 215; Cret. Rept. U. S. 1865, 76). 



The teeth of the latter animal are identical in form with the most charac- 

 teristic specimen originally referred to Trachodon, but differ in having the en- 

 ameled border of the crown tuberculate. 



Recently I have regarded Trachodon, as indicated by the teeth, as not dis- 

 tinctive from Hadrosaurus (Pr. 1868, 199). 



From my remarks that " had the remains of Thespesius and Trachodon been 

 found in a deposit of the same age I should have unhesitatingly referred them 

 to the same animai" (Cret. Rept. 84), Prof. Cope, from a misconception of the 

 meaning, has regarded Thespesius the same as Hadrosaurus. 



The difference in character of the corresponding vertebra; render the two 

 genera distinct, though, as in a multitude of other instances, they may have 

 possessed teeth nearly alike, or even identical in form and construction. 



1870.] 



