THE OnilLEID^E 



99 





Astroscliema stthlceve to J. clavigera Verr. 



Opliiozona alba is very closely allied to 0. dejiressa Lym., from the 



Philippines. 



Evidently there are very 



interesting 



relations in the geographical 



distribution of Ophiurids. The material here collected gives some hints 

 of the relation between the fauna of the West Indies and that of the Pacific. 

 However, we find that there is needed yet more information as to the dis- 

 tribution of the species before any definite results can be given. And it 

 should be well remembered that we must study the distribution of every 

 species separately. For the littoral species we refer toLiiTKEN, Additamenta 

 ad Historiam Ophiuridarum, Part II. (Vidensk. Selsk. Skrifter Kjobcnhavn, 

 5 Eaekke, Mathem. naturv. Afd., Bd. V., 186 Ij, and to Verrill, Notes on 

 the Radiata in the Museum of Yale College^ Part II. (Trans. Connecticut 

 Acad, of Arts and Sciences, Vol. I., 1867). 



Possibly we have made too many new species. It may be doubted 

 whether the two Ophwrniis species^ seminiidus and annccfcns, are really differ- 



+ 



ent from the two Atlantic species named above. " Be that as it may, if only 



the descriptions and figures are good, there cannot be much harm done: 



a few synonyms more, — this fault is easily corrected. We have thought it 



would be worse, if any species were wrongly referred to a species already 

 known, especially in a case where the identifying of such forms usually 



means that they are found in both the Pacific and the Atlantic Ocean. 



The classification of the Ophiurids is still in a rather imperfect condition. 

 Not even the families are finally settled, and several of the genera are very 

 insufficiently defined. Lyma'N', who has described so vast a number of 

 species, had not, unfortunately, mnch perception of the relations of the 

 forms. Though he had so large and excellent a material, he gives in his 

 great monograph only a very rude grouping of the genera, which affords no 

 idea of their real relations. Bell's classification (19) also scarcely expresses 

 the real relation of all the genera, though no small progress w^as made 



4 



thereby toward a natural classification. As one of the present authors (Dr. 

 Mortensen) purposes to give later a complete revision of the whole class 

 of the Ophiurids, we shall here still follow tlic ordinary method, by naming 

 the genera one after another, usually in the accustomed order. 



— _^r - t-^^TT— i" i^»iv.^Hh 



