296 Transactions of the Society. 
known type-species, described by other authors, is given. Many of 
these genera fail, as for instance “ Galumna ” for Notaspis alatus of 
Hermann, which is considered the type of the genus Oribata, which 
is earlier than Heyden’s time, and Spinttirnix, which was equivalent 
to Dufour’s earlier genus Pteroptus ; Cunaxa, which is equivalent to 
Hermann’s older genus Scirus, &c. In some cases acarologists have 
not considered that any new genus is required ; but the question is, 
are we at liberty to disregard Heyden’s name in the few cases where 
it is considered that a genus is required distinctly based on the very 
type, and that a well-known one, which Heyden gives and on his 
generic characters? With regard to this question, it must be re- 
membered that Heyden’s genus “Myobia,” for Schrank’s Pediculus 
musculi, has been universally adopted. Berlese’s view, I believe, 
is that this is because Claparede used it ; but Claparede only em- 
ployed it on account of Heyden’s earlier publication. Again, 
Berlese and Canestrini, the former as lately as 1892, employ Heyden’s 
genus ic Belba ” instead of Koch’s “Bamseus” ; and Berlese in his 
description of the genus expressly refers it to Heyden. It is true 
that I do not think that the genus Belba can be maintained, because 
it was founded on Hermann’s Notaspis cory nopus as a type ; and 
that Acarid is not a Bameeus , but a Notaspis (an earlier genus), 
even in the restricted sense in which that name is now employed ; 
therefore Trouessart, very properly, I think, uses Bamseus , and not 
Belba. The anatomy on which Belba is founded is utterly wrong ; 
it is “ Head, protothorax (sic), and metathorax separate.” This in 
the Acarina does not need any comment; Heyden was perhaps 
partly deceived by Hermann’s drawing. On the other hand, Berlese, 
Canestrini, and Trouessart adopt Koch’s name of “ Ammonia ” instead 
of Heyden’s earlier name of Cyta for Scirus latirostris Hermann, 
which is unfortunate, because Ammonia had been used long before 
Koch’s time, for a genus of Mollusca, whereas Cyta had not to my 
knowledge been previously used. The same authors also adopted 
Koch’s name “ Actineda ” instead of Heyden’s earlier Amystis for the 
genus founded upon the type of Trombidium cornigerum Hermann ; 
but this they were probably justified in doing, because Amystis had 
been employed by Savigny for a genus of Yermes in 1826, I think 
before Heyden’s date. I have thought it best to use the name 
‘ £ Cilliba ” for the genus of Uropodinse ; giving Biscopoma in brackets, 
and if zoologists consider that they are at liberty to adopt the latter 
name I shall be glad. 
Binychus. — It has been suggested thatCanestrini’s genus Fedrizzia, 
of which there is not any European representative, is closely allied 
to Binychus ; there seem to me, however, to be substantial differences. 
Uroseius. — I have not seen the adult of the only species con- 
stituting this genus. Judging from the nymph (Haller’s Uropoda 
elongata ), I should say that it is properly included in the Uropodinse ; 
