2 BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



report on the Blake ophiurans (1883), Brock's work on East Indian 

 species (1888), Liitken and Mortensen's report on the Albatross 

 Panamic ophiurans (1899), and, more recently, the great works of 

 Koehler on the ophiurans of the Travailleur and Talisman, of the 

 Investigator and of the Siboga, have added enormously to the list of 

 known species. Unfortunately, however, no one has attempted to 

 coordinate this mass of material with that contained in the Challenger 

 report, and as a result it is exceedingly difficult at the present day to 

 determine exactly what species are really valid, or to decide whether 

 a given specimen belongs to a known species or not. There can be 

 little doubt that when our present knowledge is finally systematized, 

 some, if not many, of the species here described as new will prove to 

 belong to known forms, though an honest endeavor has been made 

 to avoid the needless production of new names. Every one who has 

 done any work on ophiurans knows how difficult it is to grasp a mere 

 description without figures, even though it be very full and accurate. 

 I am therefore very grateful that the authorities of the National 

 Museum have approved of the extensive illustrating of this report. 

 And I take pleasure in acknowledging, also, with sincerest gratitude, 

 the patience and skill with which Miss Violet Dandridge has made 

 the figures. 



The classification of the Ophiuroidea as it stands to-day is little short 

 of absurd. Not for over thirty years has any attempt been made to 

 put it on a rational basis. Lyman never pretended to offer any clas- 

 sification of the group, though the material for a thoroughly scientific 

 one was put into the generic descriptions and the plates of the Chal- 

 lenger report. His knowledge of ophiuran morphology was extraor- 

 dinary and had not illness and death cut short his career, he might 

 have given us a natural and satisfactory arrangement of the class. 

 Since his day no zoologist has devoted himself to the subject with 

 sufficient concentration to warrant the attempt to set forth a rational 

 classification, and consequently I find myself obliged to follow, in this 

 report, a classification based on a compilation of the w^ork of Lyman 

 and some of his successors. The families which are adopted are of 

 very unequal value and their limits are generally hazy. In fact it is 

 difficult to discover any reason why certain genera are placed where 

 they are rather than in another family. For example the genus 

 Ophioconis is placed in the Ophiodermatida3, although it is practically 

 indistinguishable from Ophiacantha. Any limitation of the Ophia- 

 canthidse which excludes Ophioconis must exclude also a number of 

 species of Ophiacantha and even of Ophiomitra. The last genus, by 

 the way, can not be separated from Ophiacantha by any natural lines, 

 so long as the two are used in the present broad sense, and yet in the 

 current classification they are placed in different families. Lack of 

 time as well as lack of knowledge compelled me to abandon any at- 



