486 BibUographical Notice. 



found in our own seas. An arctic area in a zoogeograpMcal sense 

 must, as Marenzeller has pointed out, embrace all points which 

 come in contact with the Polar stream. 



While on the subject of distribution we cannot but draw attention 

 to another example of the resemblance between the Arctic and Ant- 

 arctic faunas. In his lately published ' Preliminary List ' Mr. Lyman 

 gives as one of the localities for a species described in this mono- 

 graph ( OpMocten sericeum) the rarely visited Marion Island. 



Of the species described one only (Antedon prolixa) is absolutely 

 new ; but of the rest, one Ophiurid and one Asterid were first de- 

 scribed by the authors of the present memoir in the pages of this 

 journal, and from the very material on which their present work is 

 based ; while the time which has elapsed since their earliest deter- 

 minations were published have, in both cases, enabled them to re- 

 consider the generic appellations of the new forms. But, though the 

 new species are comparatively inconspicuous, it does not by any 

 means follow that the specimens which the authors have had in their 

 hands have not required or received especial and careful study. In 

 the first place, fonns which extend over wide areas must exhibit a 

 not inconsiderable range of variation, and forms widely distributed 

 must be continually subjected to more or less insufiioient descrip- 

 tions at the hands of naturalists incompletely equipped for the work. 

 This vsoU become evident to any reader who will examine into 

 the length and substance of the synonymical lists which Messrs, 

 Duncan and Sladen have found it necessary to put out ; some of 

 these are so long that they not unnaturally bring before the mind 

 the question of how far we might or might not be justified in accept- 

 ing in toto the bibliographical data of our predecessors. With the 

 abundance of the opportxmities which are now afforded to all zoolo- 

 gists to write as much and at what length they please, it is obvious 

 that if lists are prepared of every collection which makes its way 

 into a museum, and if each of the quotations in these lists is to 

 find its way into a synonymic list, the natural historian of a very 

 early future will drag a chain of very considerable length ; and the 

 only possible relief will have to be found in taking the work of his 

 predecessors not at their worth, but at a very high value. 



We have been led by these considerations to institute a close 

 comparison between one of the lists given by Messrs. Duncan and 

 Sladen and that given for the same species {Strongylocentrotus ilr'6- 

 hacMensis) by the naturalist whose fame is so largely associated 

 with his work on the same group. 



Far from finding that the one is the copy of the other, or that the 

 work which the later writers have undertaken has been one of super- 

 erogation, we find something like half a score of differences between 

 them — differences, we must say, which are, as a rule, to the credit 

 of the later investigators ; though such points as the omission of the 

 page in the case of Gould, Desor, and Sars are comparatively trivial, 

 Messrs. Duncan and Sladcn's list has a greater comparative value 

 from giving the information *, while more serious omissions on the 

 * Or, in the case of Fabricius, giving it more correctly. 



