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practicable to do so. * * * Taken as a whole, the fresh-water faunas 

 of the Judith River and the Laramie are somewhat more distinct than the 

 brackish-water faunas of the same formations, and with fairly complete 

 collections it should not be very difficult to distinguish them in the labora- 

 tory. 



When we come to compare the vertebrates of the Judith River beds 

 with those of the Lance Creek deposits it becomes necessary practically 

 to ignore the mammals, inasmuch as only two species of these have up to 

 this time been discovered in the Judith River. These are Ptilodus pri- 

 mccinis and Borodon matutinus, both described by Lambe from the Belly 

 River beds of British America. The former of these fossils is related to 

 species of the same genus found in the Lance Creek beds and in the Tor- 

 rejon, the latter genus is of undetermined relationship. 



Fishes. — Beginning with the fishes, there have been described from 

 the Judith River beds eight species. In the Lance Creek beds, Converse 

 County, Wyoming, Professor Williston (Science, xvi, 1902, p. 952) found 

 materials which he refers to two of these species (Myledaphus Mpartitus, 

 Lepisosteus occidentalis) . One of these fishes, Myledaphus Mpartitus, 

 seems to be a ray. The rays are almost wholly inhabitants of salt water ; 

 hence the persistence of this Judith River freshwater form is somewhat 

 remarkable. A supposed sturgeon, Acipenser aTbertensis, found by Lambe 

 in the Belly River beds, occurs, according to Williston, in the Lance Creek 

 beds. From the Belly River beds Mr. Lambe described a remarkable 

 species of fish which he called Diphyodus. Hatcher states that similar 

 jaws are common both in the Judith River beds of Montana and in the 

 deposits of Converse County, Wyoming. From the Hell Creek beds of 

 Wyoming Mr. Barnum Brown has reported the discovery of another spe- 

 cies of the same genus. 



Tailed Amphibians. — Of the tailed amphibians, at all times rare fos- 

 sils, Cope described from the Judith River region four species, all members 

 of the genus Scapherpcton. Lambe believes that he has found one of these 

 in the Belly River beds, a fact that shows the somewhat extended distri- 

 bution of the genus at that epoch. Williston found one of the species in 

 the Lance Creek beds and Brown reported a species from the Hell Creek 

 deposits. While it is true that these fishes and amphibiaus are mostly 

 represented by fragmentary remains, these remains are usually character- 

 istic and capable of accurate comparison. That Myledaphus should reap- 

 pear after an interval allowing the deposition of 1,000 feet of marine 



