40 BUREAU OF ANIMAL INDUSTRY. 



" Type by absolute tautonymy" we accept as a rigid rule; "type 

 by virtual tautonymy " we accept at present as a recommendation, to 

 be followed unless strongly contraindicated. 



As instances in which "type by virtual tautonymy" seems to be 

 strongly contraindicated, the following may be mentioned: 



Dipetalonema Diesing, 1861a. This generic name is clearly based 

 upon the specific name Filaria dipetala Molin, 1858. Of this species, 

 however, only the male was known, and unfortunately only a single 

 specimen. 



Dicheilonema Diesing, 1861a, equals subsection Dicheilostomi, 1851, 

 represents another case in which type by virtual tautonymy (bilabiate) 

 is contraindicated, because of lack of details concerning this species. 



Dacnitis Dujardin, 1845a, seems open to doubt. The species esuriens 

 might be interpreted as a case of virtual tautonymy, but the genus 

 included Pleurorhynchus, 1786, and Dujardin knew that he was pro- 

 posing a new name for a group for which he was aware that an older 

 generic name was, from his point of view, available. Unless it is 

 interpreted that esuriens represents an indication of t} T pe (see Dujar- 

 din, 1845a, 268, 270) by virtual tautonymy, it would be our view that 

 sphderocephala is type by inclusion. 



7. TYPES OF RENAMED GENERA. 



RULE. In case a generic name, without designated type, is proposed as a 

 substitute for another generic name, with or without type, the type of either 

 when established becomes ipso facto type of the other. 



It occasionally occurs that an author uses two names for the same 

 genus in the same paper. One of these may be used in the list of 

 genera, the other in the list of species. In some cases it is evident 

 that, for one cause or another, he intentionally introduced a second 

 name; in others it is only evident that the two names are used in 

 identically the same sense. No objection seems possible in these cases 

 to interpreting the genera as representing identical groups, and as 

 they are absolute synonyms, they should take the same t} r pe. As 

 cases of this kind, mentioned in this paper, the following may be 

 cited: 



Anthuris Rudolphi, 1819a, and Spiroptera Rudolphi, 1819a. 



Enoplus Dujardin, 1845a, 230, 233, 653, and Tricontus Dujardin, 1845a, 3, 653. 



Hserucula Pallas, 1760, 1768, and Tieniola Pallas, 1760, 1768. 



Laphyctes Dujardin, 1845a, 3, 653, and Rictularia Froelich, 1802, see Dujardin, 1845a, 



280, 653. 



Leptoderes Dujardin, 1845a, 2, 653, and Leptodera Dujardin, 1845a, 108, 653. 

 Rhabditis Dujardin, 1845a, 239, 653, and Tribactw Dujardin, 1845a, 3, 653. 

 Schizocheilonerna Diesing, 1861a, 621, 710, and Tricheilonema Diesing, 1861a, 710. 



