ADVERTISEMENT 



The scientific publications of the United States National Museuni 

 consist of two series, the Proceedings and the Bulletins. 



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 newlj^-acquired facts in zoology, geology, and 

 anthropology, including descriptions of new forms of animals, and 

 revisions of limited groups. One or two volimies 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 publications comprising chiefly monographs of 

 large zoological groups and other general systematic treatises (oc- 

 casionally in several volumes), faunal works, reports of expeditions', 

 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 were 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 frotn the National Herharium^ has been published as bulletins. 



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. 



