144 



SCIENCE 



[N. S. Vol. LII. No. 1337 



The second method above mentioned, the 

 use of the oldest name within any circiim- 

 scribed family or subfamily group, is one that 

 a number of modern zoologists use, although 

 almost never with entire consistency, and it 

 needs more careful consideration than the 

 first. It possesses, it must be admitted, the 

 advantage of definiteness and of easy appli- 

 cation, but it likewise has several disadvan- 

 tages which at once become evident when we 

 attempt to apply it to all existing families 

 alike, as we must do in pursuance of the main 

 object of a nomenclatural rule. The most 

 serious of these objections are as follows: 



1. A family name would be changed when 

 any genus with an older name than any of its 

 original components is added to the group. 



2. Any transference of a generic name to 

 a genus of another family in which such 

 generic name would be older than any already 

 in that family would cause confusion in the 

 transfer of the family name, a result that is 

 always very undesirable. 



3. The universal application of this rule 

 would make wholesale changes in familiar 

 family names in almost all branches of zool- 

 ogy, since imtil recently the use of the oldest 

 genus was apparently only accidental, or be- 

 cause it happened to be the most prominent 

 or characteristic group in the family. This 

 is especially the case with the older authors; 

 and the use of the oldest generic name is not 

 by any means current practise among modern 

 writers, even entomologists, since examina- 

 tion of Dr. Dalla Torre's " Catalogus Hymen- 

 optorum " shows at once that a number of 

 the subfamily and family names that he uses 

 are evidently chosen by another method, for 

 they are not based on the oldest genus in- 

 cluded by him in their respective family or 

 subfamily groups. Merely a few of the 

 names that would have to be changed were 

 this rule of the oldest generic name enforced 

 are, in Hymenoptera : Ctenopelmatinse, Dac- 

 nusinse, Euphorinas, Tetrastiehinte, Tetracam- 

 pinse, Tridymina;; in mammalogy, Desmodon- 

 tidse, Oxysenidse, Oxyclfenidse, Chinchillidse, 

 Dasyproctidas, Erethizontidaa, Microtinse; in 

 ornithology, Ichthyornithidfe, Eallidas, Gruidse, 



Ciconiidss, (Edicnemidse, Cathartidse, Phasian- 

 idffi, Picidaa, Capitonidse, Pycnonotidse, Ploce- 

 idas and Frigillidse. 



4. Most important of all, it would prevent 

 a definite and permanent concept of the type 

 genus, since this would be constantly shifting 

 by reason of the addition, subtraction, and 

 changes of names. 



The third method for the determination of 

 the type genus is the use of the genus from 

 the name of which a family designation was 

 first formed, and the retention of this genus 

 as the family type, whatever its name be- 

 comes. The chief objection to this is that it 

 involves search through the literature for the 

 earliest dates of family names, similar to that 

 already made for generic terms. This, how- 

 ever, is not such a great task as might at first 

 appear. In fact, Agassiz, in his " ITomen- 

 clator Zoologicus," has made a substantial 

 beginning in this direction for all groups of 

 zoology; while Dalla Torre has performed this 

 service for Hymenoptera; Dr. T. S. Palmer, 

 in his " Index Generum Mammalimn," for 

 mammals; and Mr. Robert Eidgway, in his 

 "Birds of North and Middle America," for a 

 part of the birds. 



Its advantages do away with the chief 

 drawbacks of the "oldest genus" rule. Most 

 important, it provides a definite and perman- 

 ent family concept in some generic group. 

 Furthermore, it will prevent all changes in 

 family names from the addition of genera 

 or from alterations of generic names (other 

 than of the type genus) within the family; 

 it will obviate nearly all the transference of 

 family names to unfamiliar associations, with 

 the consequent confusion; and will cause 

 comparatively few changes in the current 

 designations of families. 



To adopt any rule will necessarily involve 

 some alterations in current family and sub- 

 family names, but apparently far fewer 

 changes result from what might be termed 

 the " permanent type genus " rule than from 

 that which selects the oldest generic name. 

 The latter has the advantage of easier appli- 

 cation and involves less research, but is not 

 nearly so logical nor so scientific as the rule 



