302 A. E. 1-^errill — North American Ophiiiroidea. 



the Bahamas and Cuba from the University of Iowa, under the direc- 

 tion of Prof. C. C. Nutting. This collection included onlj'- such 

 species as were obtained in less that 260 fathoms. 



The present revision and list is based on several collections that I 

 have studied, but mainly on the following : 



I. — The general collections of the Peabody Museum of Yale Uni- 

 versity, in which is included a series of authentically named West 

 Indian species, sent b}^ Dr. Chr, Ltitken, from the Museum of Copen- 

 hagen, many years ago. 



II.— A pretty full series of deep-sea species dredged hy the 

 " Blake " and named by Mr. Lyman, sent by the Museum of Comp. 

 Zoology. 



III. — The collection made by the Bahama Expedition from the 

 University of Iowa, referred to above. 



IV. — The extensive collection made by the U. S. Fish Commission 

 steamers "Albatross," "Fishhawk," and others, under my own 

 supervision, in every year from 1871 to 1887, along the American 

 coast north of Cape Hatteras, and including many deep sea species. 



Only a small proportion of those in this last named collection 

 appear to reach the West Indian faunal area, and therefore only a 

 few of the species will be mentioned in this article. A special 

 article on the Ophiurans of the north-eastern coast is, however, well 

 advanced towards completion and will be well illustrated. 



In the first part of tTiis paper, I have endeavored to revise some of 

 the larger and more difficult genera and families, and to supply 

 analytical tables, so as to enable students of this group to identify 

 the species without expending such a great amount of time as has 

 been necessary hitherto. The Amphiuridns and Ophiacanthidoe have, 

 therefore, received here more attention than other groups, for they 

 are always the most difficult to deal with. 



In this article I have generally used the same names for the organs 

 and parts that Avere used by Mr. Lyman in his various works on this 

 group, but have made a few changes. I have preferred to use oral 

 shield instead of "mouth-shield," adoral shield instead of "side- 

 moiith-shield," and oral papillm^ in place of " raouth-papilloe." In the 

 genera allied to Amphiura, I have usually called the " outer mouth- 

 papilla? " or papillaB of the second oral tentacle, the distal oral tenta- 

 cle-scales to indicate their homology with the ordinary tentacle-scales. 

 The same idea has been carried out in Ophiacanthidce. In the latter 

 group I have designated the apical "mouth-papillae" as tooth- 

 papillce. 



