Mabch 27, 1903.] 



SCIENCE. 



501 



grounds, where their sharp-pointed leaves are 

 quite annoying. 



It is not necessary to refer at length to the 

 well-known dependence of the yuccas upon 

 certain insects for the deposition of the pollen 

 on the stigmas of the flowers, since that has 

 been so frequently described by many ob- 

 servers. Such dependence seems to be gen- 

 eral throughout the group. Even in Samuela, 

 with its oddly narrowed, tubular perianth, the 

 common yucca-moth (Pronuha yuccasella) is 

 shown to be the agent in pollination. 



The monograph is richly illustrated by 

 eighty-eight plates of plants and their fruits 

 and seeds, besides twenty-four maps showing 

 the distribution of the species. American 

 botany is to be congratulated on the publica- 

 tion of this admirable monograph. 



Charles E. Bessey. 



Univeesity of Nebraska., 



A List of North American Lepidoptera, and 

 Key to the Literature of this Order of In- 

 sects. By Harrison G. Dyar. Bulletin 

 52, TJ. S. National Museum. 1902 [Feb- 

 ruary, 1903]. Pp. 723. 



For many years the guide and companion 

 of the European lepidopterist has been Staud- 

 inger's ' Catalogue of the Lepidoptera of the 

 Palsearctic Faunal-region.' The veteran au- 

 thor of that work has now died, leaving us a 

 new edition, prepared in conjunction with Dr. 

 H. Eebel. In America we have had nothing 

 equivalent to Staudinger's catalogue, although 

 Dr. J. B. Smith's useful check-list of 1891 

 served to indicate the names and classification 

 of the species. At last, however. Dr. Dyar 

 has given us a detailed catalogue, including 

 full references to literature and brief indica- 

 tions of localities. In preparing this work. 

 Dr. Dyar has been assisted by Dr. 0. H. Fer- 

 nald. Rev. Geo. D. Hulst and Mr. August 

 Busck, as is carefully acknowledged on the 

 title-page; he has also utilized previous lists, 

 so far as they proved serviceable. The litera- 

 ture of the subject has been searched with 

 extraordinary care, and full advantage has 

 been taken of the most recent advances in 

 our knowledge of the classification of the 

 Lepidoptera, many of them due to Dr. Dyar 



himself. While there are of course a few 

 errors in copying or printing, these are ex- 

 tremely few, and the work as a whole is ex- 

 ceedingly well done. If any of us are inclined 

 to regret that a man like Dr. Dyar, one of 

 the most original and gifted investigators in 

 America, should spend his time in preparing 

 a catalogue, we may console ourselves by 

 recollecting the character of some other cat- 

 alogues, prepared by men of less ability. In 

 truth, the thing was well worth while, and its 

 value to students of American lepidoptera can 

 hardly be overestimated. 



The Staudinger and Rebel catalogue for 

 the Palsearctic Region, published in 1901, in- 

 cludes the names of nearly 4,800 species. 

 Dyar's list (including 44 interpolated since 

 it was made up) includes 6,666 species, occur- 

 ring in America north of the Mexican bound- 

 ary and the West Indies. This is not pre- 

 cisely equivalent to the Nearctic region, as it 

 excludes the tableland of Mexico, and includes 

 certain Neotropical elements represented in 

 southern Florida. In all probability, our 

 region is much richer in species than the 

 Palfearctic, as it is quite certain that our lists 

 are very incomplete in respect to the smaller 

 moths. In parts of the southwest, indeed, it 

 appears that new species of microlepidoptera 

 are so abundant that the most superficial col- 

 lector can not fail to find some, while the 

 harvest to be reaped by systematic collecting 

 and breeding is almost unlimited. 



It is difficult to determine exactly the de- 

 gree of resemblance between the lepidopterous 

 faunae of the Palaearctic and Nearctic regions, 

 but while the two have even a number of spe- 

 cies in co m mon, they are in most respects very 

 different. Taking the index of the Palsearctic 

 (Staudinger and Rebel) catalogue, I find 326 

 valid genera enumerated under the first three 

 letters of the alphabet. Of these, only 97, or 

 less than 30 per cent., are found in Nearctic 

 region. The difference would seem even 

 greater if one took the names just as they 

 stand in the two catalogues, because different 

 views about nomenclature have given us in 

 many cases different names for the same 

 genus. It is very likely that a more exact 

 comparison between the Patearctic and Ne- 



