February 3, 1899.] 



SCIENCE. 



175 



crytallographic systems of Naumann, Weiss 

 and Miller, with formulas for converting the 

 symbols of one system into those of another. 

 Tenth, atomic weights of the elements. 

 Eleventh, an essay on the history of the 

 names of geologic formations, by J. Walther. 

 Twelfth, rules for the termination of proper 

 names in scientific literature. Thirteenth, a 

 brief notice of the advance of geology for the 

 year. Fourteenth, list of geologists who have 

 died since October 1, 1897. Fifteenth, table of 

 the commonly-used measures of length. Six- 

 teenth, isogonic chart of Europe for 1899. 

 Seventeenth, lists of periodicals now published. 

 Eighteenth, a list of geological, paleontological 

 and mineralogical literature for 1898. (Very 

 incomplete, particularly as regards America, 

 and frequently useless because name of period- 

 ical is not given.) Following is a chart of map 

 scales, a daily calendar, a few blank pages for 

 accounts, and blank and cross-section pages for 

 geologic notes. Then come 26 pages of adver- 

 tisements of German materials for use in geologic 

 investigation and teaching. Worthy of notice 

 among these advertisements is Professor Dames' 

 Geological Globe, of 34 cm. diameter, which 

 will be useful in every geological laboratory. 



The writer found the first edition of this 

 book an invaluable vade mecum in a European 

 trip. At home the book serves as a valuable 

 check-list for the sending of separates, for in- 

 formation concerning geologic maps, and while 

 it is not particularly adapted to the American 

 geologist it is a welcome addition to the refer- 

 ence books one keeps about his desk. A hand- 

 book for the field geologist has yet to be writ- 

 ten. Just what such a book should contain is 

 probably difficult to ascertain. 



J. B. WOODWORTH. 



The Chinch Bug. By F. M. WEBSTER. Bull. 



No. 15, N. S., Div. of Entomology, U. S. Dept. 



of Agriculture. [November] 1898. Pp. 82_ 



This excellent bulletin deals with a subject of 



perennial interest to fai-mers and entomologists ; 



and although the literature of the chinch bug is 



already large, Professor Webster has found 



plenty of new and interesting things to say 



about it. In the most interesting and convincing 



way, he shows how the insect may have origi- 



nated in Central America, and spread northward 

 in three columns, one along the Pacific coast, 

 the second over the prairie region east of the 

 Eocky Mountains, and the third along the 

 shores of the Gulf of Mexico and Atlantic ocean. 

 On p. 72 a map is given illustrating these mi- 

 grations. The Pacific column appears to be 

 weak, and is little known, but the other two 

 are strong in numbers. In the course of these 

 migrations the insects have become modified, 

 and it is clearly shown that the Atlantic and 

 prairie hordes differ both in habits and struc- 

 ture. Just at this point the present writer is 

 inclined to disagree with Professor Webster's 

 opinion, that there is only one species of -BKssms 

 in North America. There are reasons for be- 

 lieving that we have at least three species, and 

 Montandon (Ann. Soc. Ent. Belg., XXXVII., 

 1893) has described as new B. hirtiis from North 

 America, and B. pulchellus from Central and 

 South America. Unfortunately, I have not ac- 

 cess to these descriptions, but from the data 

 furnished by Professor Webster we may sepa- 

 rate the following : 



1. Form of Central America and the West 

 Indies : Macropterous, perhaps of larger aver- 

 age size than the North American type. This 

 may be Montaudon's pulchellus. 



2. Form of the prairie region of North 

 America, probably also of California : Macrop- 

 terous, more slender and less hairy than the 

 coast insect. This is doubtless Le Baron's Bhy- 

 parochromus devastator, and will be called Blissus 

 devastator (Le Baron). This insect occurs in 

 small numbers, and is evidently native, along the 

 eastern base of the Rocky Mountains, in Colo- 

 rado and New Mexico. Like the Colorado po- 

 tato beetle, it has become destructive when, 

 moving eastwards, it found the cultivated fields 

 of the central States. Professor Webster shows 

 that it is very destructive to wheat and corn, 

 but rarely attacks timothy. It has two annual 

 broods. 



3. Form of the coast region and northeastern 

 States. This is doubtless the true Blissus leu- 

 copierus, Say. It has both brachypterous and 

 macropterous forms, and is somewhat broader 

 and decidedly more hairy than devastator. It 

 depredates almost exclusively upon timothy 

 grass and is single-brooded. 



