December 26, 1902.] 



SCIENCE. 



1031 



sucker, the male parent alone attends to the 

 cleaning of the nest while it is in use by the 

 fledglings. The methods used in securing the 

 photographs, as well as the manipulation of 

 the cameras, were explained by the speaker. 

 Glover M. Allen, 



Secretary. 



DISCUSSION AND CORRESPONDENCE. 



THE STEATIGRAPHIC POSITION OF THE JUDITH 



RIVEK BEDS. A CORRECTION OF JIR. 



hatcher's CORRECTION. 



In Science of November 21 Mr. J. B. 

 Hatcher publishes a note in which he disputes 

 some statements made by Professor Osborn 

 in an article on ' New Vertebrates of the Mid- 

 Cretaceous.' One of these relates to the posi- 

 tion of the Judith River Beds, and Mr. Hatcher 

 expresses the opinion that these beds which 

 have usually been considered part of the 

 Laramie are really much older than that for- 

 mation. He says that ' The fact that Cre- 

 taceous Nos. 2 and 3 [Benton and Niobrara] 

 are entirely wanting in this region leads to 

 the inference that they are represented by the 

 lower members of the Judith River beds, and 

 that the lower members of these ]jpds are in 

 reality older than the oldest of the Belly River 

 series, a little farther north.' This inference 

 is wholly incorrect, but as it claims to be based 

 on the field ol)servations of so able and care- 

 ful a worker as Mr. Hatcher it is likely to be 

 accepted by many and to confuse all future 

 discussions of the subject if it is not promptly 

 corrected. 



It has long been known that the equivalents 

 of the Fort Pierre and Fox Hills beds under^ 

 lie the Judith River beds in their typical ex- 

 posures near the mouth of Judith River. Mr. 

 Hatcher quotes Meek and Hayden's erroneous 

 statement of 18.57, but if he had examined 

 their later references to the geology of the 

 region he would have foimd the error cor- 

 rected and that the sandstone first called 

 ' No. 1 ' was later referred to the Fox Hills 

 or ' No. 5.' * 



The section has been studied by E. D. Cope, 

 C. A. White and doubtless many others. In 



* See Meek's statement in U. S. Geol. Surv. 

 Terr, quarto Vol. IX., 1876, pp. xxxvi, xlviii, xlix. 



1894 it was the writer's privilege, in company 

 with Mr. W. H. Weed, to examine the section 

 along the Missouri River from Fort Benton 

 to the mouth of the Judith. Between these 

 two points the distance along the meandering 

 course of the river is somewhat over 100 milea 

 and the rocks are well exposed almost con- 

 tinuously from the Benton shales up to the 

 Judith River beds. By the latter term I 

 mean the brackish- and fresh-water beds to 

 which it was first applied, well exposed on 

 both sides of the Missouri River near the 

 mouth of Judith River, Montana. At many 

 places in this neighborhood these beds were 

 seen to lie directly on shales and sandstones 

 containing an abundant marine invertebrate 

 fauna which elsewhere is known to be charac- 

 teristic of the Fox Hills beds. The relation 

 of these fossiliferous marine beds to the over- 

 lying Judith River beds may be seen near the 

 mouth of Dog Creek about three miles east 

 of Judith P. O. ; on Dog Creek three to four 

 miles above its mouth; on the north side of 

 the Missouri opposite Judith; and on the 

 north side of the Missouri three miles north- 

 west of Judith. Among the species collected 

 are Cardium speciosum M. & H., Mactra alia 

 M. & H., Avicula nelyrascana M. & H., Oymella 

 undata M. & H., Splimriola cordata M. & H., 

 Callisia nehrascensis M. & H., and Tancredia 

 americana M. & H. These are sufficient to 

 establish the horizon as Fox Hills without 

 question and the overlying Judith River beds . 

 cannot possibly be very much older than the 

 Laramie. In my opinion they are Laramie. 

 The marine beds containing the faunas of 

 the Fox Hills and Fort Pierre are exposed 

 along the Missouri River for some miles above 

 the mouth of the Judith. Between these and 

 the typical Benton shales there is a series 

 of coal-bearing sandstones and shales whose 

 stratigraphic position is precisely the same as 

 that to which the Belly River series has been 

 assigned. In the Fort Benton folio Mr. Weed 

 has called this the Eagle formation. It is 

 separated from the Judith River beds by sev- 

 eral hundred feet of marine beds and the litho- 

 logic resemblance is not very close, though it 

 might be possible to confuse them in areas 

 where the section is not well exposed. 



