A discussion of certaiu questions of nomenciature, as api^lied to parasites. 179 



Absolute Identification is requisite in order to displace a modern 

 current name by an older obscure one) it is not available. 

 1782. Taenia pectinata Goeze. Available name. Is valid in case 

 acutissima is not considered available, see above. 



II. Andrya rhopalocephala (Riehm, 1881). Valid name. 



1800. Alyselminthus "^jecifma^ws (G-oeze, 1782)" of Zeder. Misdeter- 

 mination, not T. pectinata. Hence not available. 



1881. T. rhopalocepTiala Riehm; rhopalocep>hala is available. 



1893. Andrya pectinata ([Goeze, 1782] of Zeder, 1800) Railliet ; 

 pectinata is not available because it was a misdetermination. 



Railliet adopted the name Andrya pectinata, using pectinata as 

 if Zeder had proposed it. In this ruling Railliet feil into error. 

 The Int. Code (V, 3) distinctly excludes the use of pectinata in this 

 event. The reason of this will be immediately clear, when we recall, 

 that even if A. pectinatus Zeder, 1800, is considered a distinct name 

 it would be a homonym of T. pectinata Goeze, 1782, since Alysel- 

 minthus is a synonym of Taenia. 



10. The advantage of reyerting to the oldest aYailahle name. 



A number of helminthologists, and more particularly Looss and. 

 Luhe, apparently do not fully appreciate the advantage of adopting 

 the oldest name which can legitimately be given to a genus or species. 

 Such advantage will however be clear when we recall that the older 

 a name is, the less competition it has for supremacy, and conversely, 

 competition increases in proportion to the number of years a name 

 is removed from 1758. Thus, Hassall and I dated Sphaerostoma 

 1809; Looss dated it 1899. If we acknowledge the date 1809, the 

 name competes with the names (including synonyms) published for 

 only about 50 years ; if dated 1899, it must compete with the names 

 published during 140 years. The chances of its remaining available 

 in the latter case would therefore be enormously less than in the 

 former. The same point arises in connection with Brachycoelium. 



11. The type of a new genus which contains the type of an 



old genus. 



It quite frequently occurs that an author proposes a new genus, 

 not designating a type, but enumerating among the species which he 

 includes in his newly proposed group a form which is the type of a 

 preexisting genus. Such cases have given rise to no little confusion. 



