30 IOWA STUDIES IN NATURAL HISTORY 



Within the last few years the study of the ophiurans has taken 

 on a renewed impetus, and a number of large and important 

 memoirs have appeared. A rather unusual feature of this activ- 

 ity has been that all of the authors concerned have worked in 

 perfect harmony and without a trace of other than the most 

 friendly cooperation, with the result that, instead of a mass of 

 new and conflicting ideas and testily debated new genera and 

 species we have before us today an entirely new classifi.cation of 

 these animals in its perfected form only two years old yet 

 accepted by all the authorities on the subject, and an increase of 

 something like 300% in the number of known species, over 400 

 having been described by a single author, very few of which it 

 has been found necessary to place in the synonymy of older 

 forms. 



To the energy and activity of Professor Rene Koehler of Lyons 

 we are indebted for the greatest increase in the number of known 

 types, and to Professor Hikoshichiro Matsumoto of Sendai for 

 our new classification ; to Dr. Hubert Lyman Clark of Harvard 

 we are indebted not only for an important increase in the num- 

 ber of known genera and species, second only to that which we 

 owe to Professor Koehler, but also for a magnificent memoir in 

 which all of the recently described new species are included, 

 assembled under Matsumoto 's revised classification. 



The classification here adopted follows that employed in Dr. 

 Clark's memoir except that, with Professors Koehler and VerriU, 

 I recognize the family Ophiomycetidae, the genera of which are 

 placed by Matsumoto and by H. L. Clark in the Ophiacanthidae. 



The memoirs which should be consulted in connection with the 

 present paper are the following: 



Report on the Ophiuroidea Collected by the Bahama Expe- 

 dition IN 1893. Addison E. Verrill. Bulletin from the Lab- 

 oratories of the State University of Iowa, vol. 5, No. 1 (Bul- 

 letin of the University of Iowa, N. S., vol. 1, No. 6), September, 

 1899, pp. 1-86, plates 1-8. 



A Contribution to the Study of Ophiurans of the U. S. 

 National Museum. Rene Kcehler. Bulletin 84, L^. S. Nation- 

 al Museum, 1914, pp. i-vii, 1-173, plates 1-18. 



