ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 165 



which is a much greater evil than the giving of several names to one species. 

 Until, therefore, existing species are tabulated in such a way as to be recog- 

 nizable by students, it would appear a less evil in a doubtful case to de- 

 scribe a fresh species, than to run a probable risk of affiliating a different 

 shell to a species already constituted. 



16. Those identifications therefore are by far the most satisfactory which 

 are made by a comparison of types. But even here the student must exer- 

 cise caution. For if any one had searched last year for the types of Brode- 

 rip's Calyptrccidce (so obscure to the many who have not access to the plates 

 in the 'Transactions'), he would have found not only two of those species 

 nameless, and in imminent peril of re-description, and that too as from dif- 

 ferent localities from those recorded in the 'Proceedings'; but he might have 

 observed the same name of Broderip given to two distinct species, neither of 

 which was the shell figured in the ' Transactions,' which still appears under 

 another name. On searching also for the types of shells described in the 

 * Proceedings,' within a few weeks after they had been communicated, the 

 names indeed were found, but fastened to very different shells from what the 

 author had intended. All these errors had arisen from the number-tickets 

 with the shells referring to the catalogues having been misplaced. 



17- As human life is so short, and those who have the inclination for 

 scientific pursuits have generally so little leisure, it is a serious evil when so 

 large a proportion of that little has to be devoted to the labour of making 

 out the errors of predecessors. We therefore venture to suggest some points 

 which may be worthy of the consideration of the leaders in science. First, 

 whether the Government, which often spends large sums in the production 

 of important and expensive works, might not spend a portion of that sum in 

 presenting copies, or selling them at a reduced rate, to the various free mu- 

 seums and libraries in the country. Secondly, whether the British Associa- 

 tion (which has already catalogued the stars), or some other public body, 

 might not undertake the work of cataloguing the existing species in different 

 departments of natural history*. And thirdly, whether] a general registry 

 office could be agreed upon by naturalists of all nations, which might have 

 branch stations in the various capitals, and to which Latin copies of all de- 

 scriptions of new species should be sent, by every naturalist who wished to 

 retain the rights of priority ; to be accompanied by information where the 

 type specimen was to be found. 



18. But the foundation-point of all our inquiries must be the discrimi- 

 nation of species themselves as they exist in nature. And here those labour 

 under great disadvantage who can only consult the " especes de cabinet" in 

 which, for the sake of saving room, single or very few specimens are exhi- 

 bited ; since, in the case of variable species, it is quite easy to pick out 

 several extreme forms which shall apparently be even more distinct than 

 those which all allow to be separate species. Every description therefore 

 which is founded on single or extremely few specimens must be regarded as 

 only provisional, till their circumstances of variation are known. And 

 he, perhaps, is doing more useful work, who has obtained materials by 

 which a full knowledge of the variable powers of mollusks may be attained, 

 than he who only describes a number of single independent forms. Those 



* Or if this should be regarded as too great a work, the preparation of cheap digests of 

 species like Mr. Hanley's admirable ' Recent Bivalve Shells,' and figures intermediate 

 between those of Wood and the Monographs, are greatly to be desired. Now that Mr. Wood- 

 ward's text-book is making the study of Mollusks so popular, the need for such books of species 

 is becoming extensively felt. The publication also of cheap abstracts of expensive books, such 

 as are given in the ' Zeit. f. Mai.,' would be of great service to students, 



