REPORT ON THE HEXACTINL^ 9 



tiim. Verrill founded this species ('65) on a specimen from San 

 Francisco, but later ('69) gave a more complete description 

 based on additional specimens from Puget Sound. In both 

 papers he states his belief that the species is closely allied to 

 the M. marginattun of the Eastern Coast of America, differing 

 from it, however, ** chiefly in having longer and more slender 

 tentacles, with the parapet further from the margin of the disk." 

 He further suggests that M. marginatum, M. fimbriatum and 

 M. dianthiis *' will eventually be found to belong to one very 

 variable and widely diffused species. 



Andres ('83) considers M. fimbriatum a synonym for M. 

 marginatum, accepting Verrill' s suggestion to this extent, and 

 though retaining marginatum distinct for dianthus, states his 

 belief that it may be identical with that form. 



We have here two questions of synonomy to consider : (i) Is 

 M. fimbriatum identical with M. marginatum ? (2) Is either 

 of these species identical with the European M. dianthus ? To 

 the first of these questions I would answer in the affirmative. 

 I have carefully compared specimens of M. marginatum from 

 the coast of Massachusetts (Woods Holl) with the Puget Sound 

 specimens, and, allowing for the variability which seems to ob- 

 tain even in specimens from the same locality, I see no reason 

 for regarding the two as distinct. It may be well however to 

 compare in some detail the specimens from the two sides of the 

 Continent, that my conclusions in the matter may not be merely 

 ex cathedra statements. 



I. As to the coloration. It has been stated above that three 

 principal color varieties occur in the Puget Sound specimens. 

 The same three varieties are readily distinguishable in the 

 Woods Holl individuals, and, in connection with this, two points 

 of some interest may be incidentally referred to. So far as I 

 have seen in the examination of several hundred specimens of 

 the east coast form, the smaller individuals are always brown, 

 the individuals of a salmon or white color being invariably large 

 and one is tempted to suppose that the salmon and white varie- 

 ties are not distinct from the brown variety from the beginning, 

 but that the brown color is characteristic of all younger individ- 



