120 Journal New York Entomological Society. [Voi. xii. 



ARTHROPODA: General. 



THE TYPES OF GENERA. 



By Harrison G. Dyar and A. N. Caudell, 

 Washington, D. C. 



It is a self evident proposition that no stable nomenclature can 

 result until the types of all the older genera are definitely fixed. The 

 American Ornithologists Union's code decides that this shall be effected 

 by the method of elimination, and the last quarter of a century has 

 seen numerous attempts in this direction. The results, however, have 

 not equalled the expectations ; stability is apparently further off than 

 ever. We are aware of several instances where every author that has 

 dealt with a certain genus has arrived at a different species as the type, 

 all proceeding by apparently the same method. In fact the method 

 contains a fatal defect in that it tacitly requires a complete knowledge 

 of all the literature, a thing most difficult to attain. Moreover the 

 method is extremely laborious and requires a great expenditure of time 

 over a matter entirely subsidiary to the end in view, which is after all 

 the study of organic nature, not the study of a set of names. Mr. F. 

 Pickard Cambridge says :* " Elimination pure and simple in its prac- 

 tical application almost invariably lands us in an absurdity. In this 

 way, the species which the authors withdraw are usually those that are 

 best known, with characters salient and well described, leaving in 

 those least known, with this result, that the last species left in is one 

 which is not known, is badly described, and never likely to be identi- 

 fied with any certainty ; and this miserable phantom is left us as the 

 type of the genus." 



After consideration, we believe that the method of first species is 

 the only practical way of determining types and we have in mind the 

 revision of certain orders of insects on this basis. The Sphingidre 

 have been thus revised by Rothschild and Jordan,f but two of their 

 rules seem to us unwarranted. The ruling requiring generic terms to 

 be verbally defined we would not defend nor adopt. A genus is suf- 



*Ann. Mag. Nat. Hist. (7), viii, 403, 1901. 



t Revision of the Sphingidre, Nov. ZooL, ix, Supplement, 1903. 



