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ACKNOWLEDGMENTS. 



lu this Bulletin recognition should be made of the very valuable 

 services rendered by my Assistants, especially Mr. Alfred F. Sat- 

 terthwait, of Chester county, Clerk in the office of the Economic 

 Zoologist. Mr., W. K. McConnell, Indiana county. Assistant, and 

 Mr. P. H. Hertzog, of Lancaster county, Assistant, have taken great 

 interest in this subject and have rendered valuable help that was 

 essential in working out the details of this Bulletin. To the intelli- 

 gent and indefatigable industry of Mr. Satterthwait, my clerk for 

 more than a year, much credit is due. 



We wish also to recognize the generosity and help that was given 

 us by Mr. W. H. Fisher, 1318 Bolton street, Baltimore, Md., who 

 contributed many of the excellent photographs of the living speci- 

 mens which are used in making the plates for the Bulletin, and which 

 give it an added interest. 



We should also acknowledge the free use that has been made of 

 the "Manual of Vertebrate Animals of the Northern United States," 

 by President David Starr Jordan, and such literature as the publi- 

 cation of ''Reptiles of Allegheny County, Pa.," by D. A. Atkinson, 

 in the AnnaJs of Carnegie Mvseum, Vol. I, and the Report of the 

 Amphibians and Reptiles of New Jersey, by Dr. Witmer Stone, 

 Philadelphia Academy of Science, in the Ainerlcan Naturalist for 

 March, 1906, and other literature which will be cited in detail in 

 the Second Report. 



Acknowledgment should also be made of the assistance of such 

 persons as Dr. Witmer Stone, Philadelphia, Mr. D. A. Atkinson, 

 Carnegie Museum, Dr. R. L. Walker, of Carnegie, Pa., and others. 

 Special mention should be made of the industry and skill of Mr. 

 \V. R. Walton, the artist in our office, who has taken an unusual 

 interest in this subject and has been at great pains to have the 

 charts and drawings which were made by him exactly accurate in 

 all their details. 



H. A. S. 



