Bihliographical Xotices. 453 



Heusel. Misled by an authority, who shall be nameless, 

 and by the fact that an important paper by my friend 

 Dr. Forsyth Major was published in a foreign tongue with 

 which I was at tbat time unacquainted, I erroneously con- 

 cluded that Dr. Forsyth Major considered Mus orthodon to 

 be a very near ally of Mas sylvuticus. His real opinion, 

 published in the Proc. Verb. Soc. Tosc, Sci. Nat. 1884, was 

 very different, as he now informs me, and I believe I am 

 right in saying that it coincides with that at which 1 myself 

 independently arrived in my paper of 1900. 



Although, then, no difference of opinion exists between us 

 on any question of fact, I fear that those who read my paper 

 might easily conclude otherwise, and they would certainly 

 gain a false impression — due to my having followed too 

 blindly the above-mentioned "authority'^ — of the value of 

 Dr. Forsyth Major's work. To remove any such misunder- 

 standings is the object of this letter, an explanation being 

 clearly due to Dr. Forsyth Major, against whom I can 

 formulate no complaint more serious than that so many of 

 his most luminous papers on Palsarctic mammalogy should 

 have been published in foreign journals often not readily 

 accessible. 



I am, yours truly, 



G E. H. Barrett- Hamilton. 



BIBLIOGEAPHICAL NOTICES. 



Economic Eesources of the Northern Black Hills. By J. D. Irtixg. 

 "With Contributions by S. F. Emmons and T. A. Jaggae, Jr. 

 Pages 222. 4to. Government Printing Office, Washington, 

 1904. 



This volume, published as " No. 26 " of the " Professional Papers : 

 Series A. Economic Geology, 34 ; B. Descriptive Geology, 38," 

 consists of Part 1. General Geology, by T. A. Jaggar, pages 17-41; 

 and Part II. Mining Geology, by J. D. Ii-ving and S. F. Emmons ; 

 214 pages, 19 plates, and 15 text-figures. Lastly, the Index, 

 8 pages. 



This is one of the very useful contributions by the U.S. Geological 

 Survey to the inhabitants of a definite area of the recognizable 

 features and structure of the land, systematically considered, as well 

 as of its products and capabilities. 



All notices of the Geology of the district already published are 

 duly mentioned at page 13. 



The Black Hills in South Dakota have a dome-hke structure of 



