A discussion of certain questions of nomenclature, aa applied to parasites. X93 



pora as type, and examining it, make up his mind as to which char- 

 acters were more important: 



4) One might lay special stress upon the suckers, and declare 

 Podocotyle [type, D. angulatum Dujardin, 1845, not known to Ru- 

 DOLPHi ^)] as synonym of Sphaerostoma. 



5) Another might take the intestine as character and make Dicro- 

 coelium [type B. lanceatum Stiles et Hassall, 1896, misdetermined 

 by RuDOLPHi] synonymous. 



Replying to Looss' position I would submit, in the first place, 

 that in referring to Rudolphi's Sphaerostoma and selecting glohiporum 

 as type, we were not carrying out any new or revolutionary ideas, 

 but were simply performing a duty which devolved upon us, and do- 

 ing so strictly in accordance with precedents which for 

 years have been recognized by nomenclaturists. Looss' 

 criticisms are due solely to the fact that — as admitted by himself 

 on p. 523 of his article — he is unacquainted with these customs 

 estabhshed by precedent, hence his position can be very readily under- 

 stood; while of his four suppositions of what some one eise might 

 have done, two are unallowable and two improbable. 



One of the fundamental rules of nomenclature is, that a generic 

 name once established cannot be ignored in any subsequent subdivision 

 of the group, but must be retained — if otherwise valid — for some 

 portion of that group containing one of the original species. The 

 generic name Sphaerostoma had been printed; we considered it then 

 — and we do to-day — published in such a way as to deserve atten- 

 tion, hence we feit obliged to include it in our list, It is certainly not 

 anomen nudum. At most, it may be objected that Rüdolphi 

 failed to mention directly any species in connection with it, and that 

 he gave a poor diagnosis. One does not, however, have to take refuge 

 in conjecture to see what Rüdolphi referred to. To us, at least, it 

 is clear (I cannot of course speak for Looss) that Rüdolphi had 

 certain species in mind; any one of these species may come 

 into consideration in the selection of a type. We are not 

 at this date compelled to take one which he had e s p e c i a 1 1 y ("speciell") 

 in mind, although it would be wiser to do this. 



In the first place: '■''potissimum in piscibus ohviae'" immediately 

 confines our attention to those fish distomes (Hemiurus, of course, ex- 

 cepted) which Rüdolphi mentioned between p. 352 and 415. 



1) But D. gihhosum might have been taken. 



