Geology and Mineralogy. 465 



well says : " The author feels confident that the glacial explana- 

 tion is most convincing to students of geography, who . . . have 

 not either lived in or even seen any region of former or present 

 intense glaciation. Only to such workers does the whole series 

 of novel perceptions presented during a first glimpse at a former 

 strongly glaciated region come with the startling force of a reve- 

 lation." w. m. r>. 



4. Mastodon- Reste aus dem inter andinen Hochland von Bo- 

 livia ; von J. F. Pompeckj. Palaeontographica, Bd. 52, 1905, 

 pp. 17-56, 2 pis. —Dr. Pompeckj, during his travels in Bolivia in 

 1902, collected near Ulloma and Calacoto a number of mastodon 

 jaws and teeth here described and discussed in great detail. 

 These were found at an elevation of 3800 meters above sea level, 

 and belong to Mastodon bolivianos and M. humboldti. 



The belief is held by some that these mastodons lived at a 

 time when the mountains had a far lower altitude than now, but 

 Pompeckj holds quite the contrary opinion. He states : 



"During Diluvial time, or at least during that portion of it 

 when the fauna containing Mastodon bolivianus existed, the high 

 Bolivian plains at an elevation of about 3800-4000 meters prob- 

 ably had the character of a steppe, similar to that of to-day, but 

 with a greater rainfall and therefore with a richer growth of 

 grass and bushes than at present. 



"Neither the geological structure of the Bolivian highland nor 

 its Diluvial fauna compels the conclusion of decided Diluvial or 

 Postdiluvial elevation of the Andes." c. s. 



5. Description of JVeio Rodents and Discussion of 'the Origin 

 of Daemonelix ; by O. A. Peterson. Mem. Carnegie Museum, 

 ii, 1905, pp. 139-191, text figures and pis. 17-21. — The part of 

 this paper of greatest interest in general paleontology relates to 

 the interpretation of the so-called "Devil's corkscrews," so well 

 and fully described by Professor Barbour. The general explana- 

 tion has been that these gigantic screw casts are the fossilized 

 and infiltrated roots of water plants. However, the suggestion 

 has also been made that they represent the burrows of some fos- 

 sorial rodent. 



Last year Mr. Peterson made a careful search for vertebrate 

 fossils in the Daemonelix beds as exposed in the adjoining 

 counties of Sioux in Nebraska and Converse in Wyoming. He 

 states that one is always sure to find rodent remains in a locality 

 where Daemonelix is found in great numbers, and he was 

 rewarded in his exploration by securing a number of good skele- 

 tons of the beaver-like Steneofiber within the spiral of Daemone- 

 lix or its so-called rhizome. This led him next to study the 

 tunnels of the living prairie-dog so common throughout the semi- 

 arid region of the West. He did this by making a mixture of 

 plaster, water, and sand, and pouring this into and filling the 

 tunnel. Later this filling was dug out, and two of these casts are 

 illustrated in the paper here reviewed ; they certainly suggest 



