to the British Hemiptera Heteroptera. 281 
- Passing to the remarks on the Fabrician genera, Mr. Dallas 
is well enough able to take his own part in explaining why, 
when revising the genus Cydnus, he retained the name for a 
single species; nor do we care to inquire why Fieber, Gerst- 
aicker, and Birensprung differ in their interpretation of the 
genus; for, as we see by the light of what has been done in 
other orders, there was no rule to guide them, and we believe 
that all are wrong in principle, as shown above. 
As to Tetyra, Fab., it was Laporte, and not Fieber, who 
eliminated certain species of that genus under the name of 
Eurygaster ; and it is therefore improper still to refer them to 
Tetyra by the authors quoted. From Asopus, Burm., Amyot 
and Serville selected A. cerulea (which can only be considered 
at most a type of part of Burmeister’s genus) as the type 
of anew genus (Zicrona); and the European species of Asopus, 
except /uridus, having been referred by different authors to 
other genera, duridus was the only one left for Fieber to take 
as the representative of the genus; but it would have been 
better if, as Mr. Pascoe says, he had employed Herrich- 
Schiffer’s name Podisus, as he has indicated in the ‘Schliissel.’ 
2. “Giving new names to such genera as were formed by 
the union of two or more genera of a preceding writer.” 
- The argument of this objection is met by anticipation in the 
foregoing remarks ; for it cannot be said with any truth that 
the name of a thing should be retained for another thing which 
is differently constituted, but of which the former may be an 
ingredient. A chemist when he combines two or more elements 
does not give the name of any one of them to the resulting 
compound ; neither can it be rightly done in the labours of the 
naturalist. We heartily wish it could. 
Whether or not the names we have given to the combinations 
of the genera mentioned will stand is a very small matter, if 
the union of species proposed be received as good. Nor are 
we anxious on this latter point, as we do not attach an exag- 
gerated importance to genera as now understood, regarding 
them rather as useful for classification than absolutely natural 
divisions*, Microsynamma, Fieb. (MS.), was discarded for 
Neocoris because it was not intended for more than one species, 
and the characters drawn for it would not include Plagiognathus 
Bohemani, which is now by us associated with N. Scott?. 
_* Fior’s trinomial nomenclature, which Mr. Pascoe thinks is “rather 
difficult to explain,” is easy to understand, as the first generic name is 
used in a collective or “family” sense, and the second as subgeneric. 
But the device is cumbrous, and especially inconvenient for quotation ; 
the purpose intended would have been better served by a reference of the 
genera (or subgenera) to families (or subfamilies). 
Ann. & Mag. N. Hist. Ser.4. Vol.i. 21 
