ADVERTISEMENT 



The scientific publications of the United States National Museum 

 consist of two series, the Pivceedings and the BuJlefins. 



The Proceedings^ the first volume of which was issued in 1878, 

 are intended primarily as a medium for the publication of original, 

 and usually brief, papers based on the collections of the National 

 Museum, presenting newly-acquired facts in zoology, geology, and 

 anthropology, including descriptions of new forms of animals, and 

 revisions of limited groups. One or two volumes are completed an- 

 nually and copies of each paper, in pamphlet form, are distributed, 

 as soon as published, to libraries and scientific organizations, and to 

 specialists and others interested in the different subjects. The date 

 of publication is recorded in the tables of contents of the volumes. 



The Bulletins^ the first of which was issued in 1875, consist of a 

 series of separate pul)lications comprising chiefly monographs of 

 large zoological groups and other general systematic treatises (oc- 

 casionally in several volumes), faunal works, reports of expedition?, 

 and catalogues of type-specimens, special collections, etc. The ma- 

 jority of the volumes are octavos but a quarto size has been adopted 

 in a few instances in which large plates Avere regarded as indis- 

 pensable. 



Since 1902 a series of octavo volumes containing papers relating to 

 the botanical collections of the Museum, and known as the Contribu- 

 tions froTti the National Herbarium,^ has been published as bidletins. 



The present work forms No. 130 of the Bulletin series. 



William deC. Ravenel, 

 Administrative Assistant to the Secretary, 

 In Charge of the United States National Museum. 



Washington, D. C, May 13, 1925. 



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