Geology and Mineralogy. 179 



Since there was no obvious break in the sedimentation, it is prob- 

 able that the larger part of the area was covered by low-lying 

 swamps and lagoons. For some time there were slight oscilla- 

 tions that occasionally for brief intervals brought large parts of 

 the area down to sea-level and gave the lagoons sufficient connec- 

 tion with the ocean to allow the growth of oysters and other 

 brackish-water forms over areas that had been occupied by fresh 

 waters. Then for a longer period, during which 300 or 400 feet 

 of sediments were formed, there was no connection with marine 

 waters, though it is not probable that the area was ever very 

 many feet above tide. During this epoch the general upward 

 movement was reversed, and when the subsidence progressed 

 more rapidly than deposition connection with the sea was soon 

 again established, bringing in, first, brackish waters with their 

 oyster beds, over nearly the entire area, with probably local bays 

 and straits having more open and direct oceanic connections, 

 such as is indicated by the occurrence of marine fossils in the 

 Judith River on Cow Creek. Finally marine conditions were 

 fully established over the entire area, so far as known, and con- 

 tinned during the deposition of the Bearpaw shales." 



The fossil plants of the Judith River beds are described by 

 Knowlton. There are 28 species. Of these, 8 are conifers, " and 

 when the actual number of individual specimens is considered it 

 is safe to say that fully nine-tenths belong to these species." 



"It appears that the flora of the Judith River beds that has 

 thus far come to light shows very little affinity with the true 

 Laramie or the Fort Union, but does exhibit an undoubted rela- 

 tionship with that of the Dakota group or with the Cenomanian 

 and Senonian of the Old World, or, in broad terms, with the 

 lower and middle portions of the Upper Cretaceous." c. s. 



3. Paleontology of the M alone Jurassic Formation of Texas; 

 by F. W. Ceagin. Bull. 266, U. S. Geol. Surv., 1905, pp. 172, 

 pis. 1-29. — It is not often that American Paleontology is enriched 

 by a work describing a marine Jurassic fauna, and this bulletin 

 is therefore all the more desirable. The region from which the 

 fauna was gathered is about Malone Mountain, or about 75 miles 

 southeast of El Paso, in Texas. On the basis of the ammonites, 

 this fauna shows the closest affinities with that of the Tithonian 

 of Europe. The nearest relations of American localities with 

 that of Malone are in Mexico, having been described by Castillo 

 and Aguilera. The relation of the Jurassic with the overlying 

 Lower Cretaceous could not be made out, because no continuous 

 section connecting the two systems was seen. An important 

 feature of this work is a chapter of eleven pages by Stanton, 

 entitled " Stratigraphic notes on Malone Mountain and the sur- 

 rounding region, near Sierra Blanca, Tex." 



The fauna consists of: Corals, 1 (new); Echinoidea, 2 unde- 

 termined forms; Vermes, 3; Bryozoa 1 (new) ; Pelecypoda 56 

 (40 new) ; Gastropoda, 18 (17 new); Cephalopoda 10 (5 new). 

 No land vertebrates were seen, only fragments of fishes and 

 swimming reptiles. c. s. 



