A CONTRIBUTION TO THE STUDY OF THE OPHIURANS 

 OF THE UNITED STATES NATIONAL MUSEUM. 



By RENE KOEHLER. 



Professor of Zoology, University of Lyon, France. 



INTRODUCTION. 



The United States National Museum has been kind enough to entrust to me the 

 study of a considerable collection of ophiurans coming chiefly from the Caribbean 

 Sea, and including both littoral and deep-sea forms. 1 This collection contains a 

 certain number of new species additional to those already discovered by the United 

 States Coast Survey steamer Blake in the same waters. Among the species which 

 are already known, many are very common and offer no special interest, but there 

 are also a good many others the characters of which have not been indicated by 

 the authors in a satisfactory manner, so that I have found it necessary to study 

 them in detail. Among them, I have particularly devoted my attention to the 

 species of AmpUura and OpfiiacantTia, both genera being understood in the widest 

 sense. It seemed to me useful not to limit my observations to the species repre- 

 sented in the collection which had been entrusted to me, but to extend them to 

 certain neighboring forms, the knowledge of which was likely to help toward an 

 understanding of the former. I will describe and illustrate these forms in the 

 present paper and I think that I shall not be reproached with having made it too 

 long through such additions. 



For such a comparative study, I had to have recourse to the examination of 

 a certain number of type-specimens, the most important and most numerous of 

 which had been described either by Liitken or by Ljungman. These types, which 

 are kept in the Stockholm Museum and in the Copenhagen Museum were most 

 kindly communicated to me by Professor Theel and my very good friend Doctor 

 Mortensen, to whom I beg to tender my best thanks for their kindness. The United 

 States National Museum communicated to me also a few of Professor Verrill's 

 species. 



The collection which has been handed to me includes in all 129 species, of which 

 24 are new. Here is a list of them: 



Family OPHIODERMATID^E. 



Ophiodmna appressa (Say). 

 Ophioderma bremcauda Liitken. 

 Ophioderma brevispina (Say). 

 Ophioderma cinerea M filler and Troschel. 

 Ophioderma rubicunda Lutken. 



Ophioderma variegata Lutken. 

 Ophioderma clypeata, new species. 

 Ophioderma, species. 

 Ophiarachnella angulata (Lyman). 

 Bathypectinura tessellata (Lyman). 



i To complete the published records of West Indian ophiurans in the United States National Museum a list is appended 

 of specimens identified by the Hon. Theodore Lyman but never reported on. 



