1886.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



259 



An importaut work of reference with respect to the Echini of the 

 west coast of America is the following by Prof. A. E. Verrill : 



Notes on the Radiata in the Museum of Yale College, with Descriptions of new- 

 Genera and Species. Trans. Conn. Acad. Arts and Sci., vol. i, part 2, pp. 247-(;i:?, 

 pis. iv-x, 1S67-'71. 



In the present catalogue, the arrangement of the record of specimens 

 under each species is mainly in accordance with the plan that has gen- 

 erally been followed by the Departments of Fishes and Marine Inverte- 

 brates in preparing National Museum lists, exceptiug that the writer 

 has found it more convenient for reference to place the Museum cata- 

 logue numbers at the end of each entry, inclosed in parentheses, instead 

 of before it. The entries are arranged geographically from the north 

 toward the south, and are frequently grouped under a few geographical 

 headings to facilitate reference and to permit of brevity. Where species 

 are represented from the Atlantic coasts of both Europe and America, 

 the specimens from the former country are first recorded ; aud where, 

 as in the case of Strongylocentrotus DrohacJiiensis, we have species com- 

 mon to both the Atlantic and Pacific Oceans, the former region is given 

 preference over the latter in the list. 



With the Fish Commission specimens, the locality is generally given 

 first, followed by the depth of water, the character of the bottom, 

 the number of the dredging station, and, finally, the National Museum 

 catalogue number. Where specimens are combined from several sta- 

 tions, this order is not always followed. 



The following geueral abbreviations have been used: U. S. Fish 

 Comm., for U. S. Fish Commission ; U. S. Expl. Exped., for tbe Wilkes 

 United States Exploring Expedition; N. Pae. Expl. Exped., for the 

 North Pacific Exploring Expedition; Mus. Comp. Zool., for the Museum 

 of Comparative Zoology at Harvard College; fath., for fathoms; sta., 

 for station. 



The abbreviations employed to designate the character of the bottom 

 immediately following the depth of water are explained in the follow- 

 ing table: 



The writer is under many obligations to Mr. Alexander Agassiz for 

 the opportunity of making comparisons with the unrivaled collection 

 of Echini at the Museum of Comparative Zoology, and for personal 

 assistance in identifying several difiicult species. He is also greatly 

 indebted to Mr. J. Walter Fewkes, of tbe same museum, for kind assist- 

 ance in his work at the time of making these comparisons. 



