228 BRITISH TYEOGLYPHID^. 



genus Homopus to receive them ; but this genus was 

 formed entirely upon an immature (hypopial) form, 

 and on characters which depended solely upon that 

 stage ; moreover the name was preoccupied. 



The next writer, practically, who dealt with any of 

 the creatures of this group was Kramer; he found a 

 species upon the mole, and created a new genus for it, 

 Labidophorus, having evidently overlooked the identity 

 of his genus with Koch's Homopus; being next in 

 order of date, and Homopus having failed, Kramer's 

 generic name would have stood had it not been for two 

 objections, viz. firstly, it was based on an immature 

 (hypopial) form, and depended solely upon the charac- 

 ters of that stage just the same as Koch's genus ; and 

 secondly, it is very doubtful whether this name also is 

 not preoccupied, Scudder's earlier name in Orthoptera 

 differing from it only in having a feminine termination 

 instead of a masculine ; as to whether this is sufficient 

 there is grave difference of opinion between zoologists. 



The only authorities exactly in point which I am 

 aware of are (1) the exception " a " to 4 of the rules 

 for the scientific naming of animals, issued by the 

 German Zoological Society ; and (2) Article 21 of the 

 Rules of Nomenclature, adopted by the Zoological 

 Congress, at Moscow, in 1892. In the former, after 

 stating (in the rule) that names of the same origin and 

 only differing from each other in the way they are 

 written are to be considered identical, and giving 

 examples, it proceeds : " (a) On the other hand, it 

 is permissible to use both Pious and Pica, etc." The 

 latter rules state, " Names should be avoided which 

 only differ from one another in their masculine, femi- 

 nine, or neuter terminations." 



The next author who dealt with the group was 

 Haller in 1880; he found Koch's species, but he also 

 found and described the adult form, and his genus was 

 based upon it. Therefore, for the reasons given at 

 page 187 of this work, I consider that Haller 's name 

 of Dermacarus, which he then gave to the adult, should 



