DALL ; CIRCE VersUS GOULDIA. 6 1 



must agree to differ. A good deal of investigation into that 

 topic has impressed me that, until the nomenclature of moUusks 

 is in better state, no general advance in interest in systematic 

 malacology or ease in grasping its principles can be hoped for. 

 Consequently I am (perhaps too much) inclined to insist on a 

 strict construction of the "Rules," no matter what familiar 

 names suffer. Only, as our western miners have it, " when we 

 get down to bed rock," in this way can uniformity be hoped for 

 and the nomenclature serve its only legitimate purpose, that of 

 a consistent index to the organisms it is applied to. Absolute 

 values differ with different students. One speaks of a certain 

 group as a family and a genus ; another as a sub-family and a 

 sub-genus. One says this is a species ; another claims the 

 organism as a variety : still another believes it an aggregation of 

 several specific forms. This is inevitable, and all we can expect 

 of students is a general agreement in relative values. That one 

 man's genus and species and variety shall bear such a relation 

 to one another as the other man's sub-family, sub-genus, and 

 group of species or what not. In most cases the general idea 

 of what constitute a species is pretty uniform, but it is quite 

 the other way in regard to sub-genera and genera. This is so 

 well known that few, if any, naturalists may be found who would 

 claim that so far as nomenclature is concerned it makes any differ- 

 ence iu the treatment of a name whether it was proposed as a 

 sub-genus or a genus. In any case the student will classify it 

 as he estimates its rank : one in one category, others in the 

 other category. 



Now, as I understand the case of Gouldia, it is this. Dr. 

 Gould's name was attached to two species of small bivalve 

 shells by Prof. Adams at a certain date. He designated neither 

 as the type, but in accordance with the practice of naturalists 

 I have taken the first, largest, and most conspicuous species of 

 the two as a type. If there was any one thing new in the group 

 which had not before been generically distinguished it was en- 

 titled to bear the name of Gouldia, If there was more than 



