198 CH. WARDELL STILES, 



bis new genus differs from Dujardin's Brachycoelium. And if any 

 author subsequent to Dujardin, 1845, does propose a new genus which 

 corresponds to Brachycoelium witliout showing wherein the two genera 

 differ, it is natural and just to consider the later genus a synonym 

 of the earlier until some one does show a difiference between the two 

 either by mentioning a character of generic importance or by rede- 

 fining Dujardin's genus so that such ditferences will be brought out. 

 It is but natural, and in accordance with the principles of systematic 

 zoology, that in the latter event he shall designate type species for 

 both genera; and in selecting the type for Brachycoelium, it is but 

 natural that he shall notice the following facts: 



1) None of the five original species bear the name Brachycoelium 

 or its equivalent, as specific name; 



2) It is not apparent that Dujardin (pp. 381 — 389, or pp. 402 — 

 404) had any one species in mind more than any other ; although he 

 examined all five forms; 



3) Dujardin did not give any figures of any of the forms; 



4) The diagnoses are all apparently about equally complete; 



5) None of the species had ever been selected as type of any 

 other genus. 



Hence all other things being equal, any one of these five species 

 might be selected as type. In considering the other Clements which 

 enter into the subject it may be noted: 



6) The oldest species mentioned are D. clavigerum and D. crassi- 

 colle; of these, D. clavigerum is a misdetermination, hence ceteris 

 paribus, crassicolle would appear to be less liable to lead to confusion, 

 if taken as type, than would be D. clavigerum. If therefore the prin- 

 ciple supported by some workers (namely to select the oldest species 

 as type) were followed, D. crassicolle would be the type. 



7) The first page on which any species is mentioned in connection 

 with Brachycoelium, is p. 386, and D. crassicolle is that species. With 

 all those systematists who follow strict page-precedence, crassicolle 

 would on this account be selected as type. 



8) Of the five species mentioned, Dujardin refers to figures of 

 two: ''''D. clavigerum''' [misdetermination] and D. crassicolle. The figures 

 of D. clavigerum, it would appear best to leave out of consideration 

 because of the misdetermination, hence D. crassicolle remaius. 



While it is not necessary to rule in favor of D. crassicolle be- 

 cause of 6, 7, or 8, still unless reasons can be advauced to show that 

 it would be better to select some other species as type, it is clearly 



