THE ANNELIDS OF THE FAMILY ARENICOLID^J OF NORTH 

 AND SOUTH AMERICA, INCLUDING AN ACCOUNT OF 

 ARENICOLA GLACIALIS MURDOCH. 



By James Hartley Ashworth, 



Lecturer in Invertebrate Zoology, University of Edinburgh. 



INTRODUCTION. 



The account of the Arenicolidse which is given in the following 

 pages is based chiefly on material in the U. S. National Museum, to 

 the authorities of which institution I am greatly indebted for their 

 kindness in sending to me for examination the whole collection of 

 specimens belonging to this family of Polychseta. My thanks are 

 also tendered to many others who have helped me with the gift 

 or loan of specimens, and I would mention especially Prof. LI. C. 

 Bumpus, Dr. H. P. Johnson, Dr. W. McM. Woodworth, Prof. A. D. 

 Howard, Prof. C. A. Kofoid, Dr. R. S. LilHe, Prof. H. Heath, and 

 Prof. A. L. Treadwell. 



In addition to the material received directly from the LTnited States, 

 I have also examined a considerable number of specimens from 

 American sources now deposited in various museums in Europe. 

 I hoped to obtain suflicient material to enable me to give a moderately 

 complete account of the distribution of the American species of 

 Arenicola, but, up to the present, the only regions from which material, 

 adequate enough for this purpose, has been obtained are the eastern 

 coast of North America and the extreme south of South America. 

 The stations from which specimens have been taken on the west 

 coast of North and South America are so few that the limits of dis- 

 tribution of the two or three species concerned must be left quite 

 indeterminable, and there are no specimens recorded from the east 

 coast of South America, nor have I been able to obtain any although 

 I have made inquiries for them from several likely sources. It is 

 to be hoped that collections from the west coast of North America 

 and from the seaboard of South America may soon be forthcoming, 

 which will provide the material necessary for the determination 

 of the range of the various species. 



Proceedings U. S. National Museum, Vol. 39— No. 1772. 



