856 HISTORICAL GEOLOGY. 



4. Lakamie Beds at Judith River {Rep. Hayden Survey, vol. ix., 4to), according to 

 Meek, in the lower part : Unio Dance and U. Dewey i, Viviparus, Goniobasis, Sphceruim, 

 Planorbis, Ostrea suhtrigonalis ; in tlie upper part: Ostrea subtrUjonalis (J), Corbicitla 

 occidentalism C. cytheriformis, Goniobasis convexa, etc. 



Among Vertebrates of the Laramie beds are the following : At Moreau River, South 

 Dakota (west of the Missouri), the Plesiosaurids, Plesiosaurus occiduus and Ischyro- 

 saurus antiquus, both described by Leidy. At the Judith River Basin, remains of species 

 related to the Iguanodon of the genera Palceoscincus, Troodon and Aublysodon of Leidy ; 

 according to Marsh, of Claosaurus, of Ceratopsids and Ornithomimus ; of Plesiosaurus 

 and Ischyrosaurus ; also of the Rhynchoceph, Champsosaurus profundus Cope; and. 

 Turtles of the genus Compsemys. At Black Butte, the Ceratopsid, Agathaumas sylvestris 

 Cope. At Castle Gate in southwestern Utah, an important coal-mining village, a species 

 of Claosaurus ; in the Denver group, or Upper Laramie, near Denver, species of Ceratops 

 and Ornithomimus. Some of the Mammals of the Laramie are mentioned on pages 852, 

 853. 



Aublysodon mirandus of Leidy (1859, 1868), referred by him to the tribe of Dinosaurs, 

 was based on a number of teeth. Marsh has suggested (1892) that some of the incisors 

 figured may be Mammalian, stating that only the discovery of a tooth of the kind in a jaw 

 will remove doubt. 



Fossils from the Cretaceous formation of New Jersey were first described by the 

 excellent naturalist of Philadelphia, Thomas Say, in 1820 {Am. Jour. Sc, ii., 34), who then 

 named species of Baculites, Exogyra (instituting this genus), and Terebratula. The beds 

 were called by him "the New Jersey Alluvium." The first reference of the beds to the 

 Cretaceous formation, and first account of their geographical distribution along the Atlantic 

 and Gulf borders, was made by Lardner Vanuxem in January, 1828 {Acad. iV. S. Philad., 

 vi.) ; and the first systematic description of the fossils, with figures, by S. G. Morton, 

 in a paper of the same date, which follows Vanuxem's. Vanuxem, in a note to his paper 

 (page 63), alludes to Morton's extensive collections of fossils of New Jersey and Dela- 

 ware, which he had examined in addition to his own. Morton's paper was soon followed 

 by others in continuation. 



The Radiolarians found by Tyrrell in the Montana group, Manitoba, have been 

 described and figured by D. Riist {Canada Survey, 1892). 



On the Invertebrate paleontology of the Continental Interior, see especially the publi- 

 cations of Meek in connection with the Hayden Survey and also elsewhere ; also papers 

 by C. A. White, and his Correlation of the Cretaceous ; also T. W, Stanton's Colorado 

 Formation (1893). 



FOREIGN. 

 ROCKS — GENERAL DISTRIBUTION. 



The Cretaceous formation covers a large part of southeastern England, 

 east of the Jurassic boundary, from Dorset on the British Channel to 

 Norfolk on the German Ocean ; and also a narrow coast region, about and 

 south of Flamborough Head, as shown on the map, page 694, and small areas 

 in northern Ireland and on the islands of Mull and Morven, off Scotland, 

 where it is covered by Tertiary basaltic lavas. 



Like the Jurassic, it reappears across the British Channel in France and 

 Denmark, and to the east and south over much of Europe. It usually out- 

 crops along the borders of the great Tertiary areas or within them, indicating 

 that the seas of the early Tertiary, which cover so large a part of the conti- 



