170 On Generic Nomenclature. 



6. The cricket is Acheta in England, Gryllus in France. 



7. The bug is Cimex in England and France, and Acanthia 

 in Germany. 



If such confusion exist in such well-known tribes of insects, 

 it may be very easily conceived what sources of perplexity 

 exist when several authors are engaged upon any particular 

 and especially difficult group of small or obscurely charac- 

 terised tribes ; instances of which I proposed to notice, con- 

 tained in the last three works published in this country upon 

 entomology ; namely, Stephens's Illustrations, Curtis's Genera, 

 and Shuckard's Fossorial Hymenoptera. 



The first of these authors, in his sixth volume of mandi- 

 bulated insects, has described twenty-eight species of the tri- 

 chopterous genus (Leptocerus of Leach), which he divides 

 into three sections. No typical species is stated ; but the first 

 six species (composing the first section), instead of comprising 

 the species for which the author should retain the generic 

 name Leptocerus (in case of division in the genus, which, he 

 says, is probable), comprises species of which Latreille formed 

 his genus Mystaxis (Mystacide); Leach's real type of the 

 genus, L. interruptus, being the twelfth species in the middle 

 of section 2. In like manner, the first section of the genus 

 Limnephilus of Leach (which ought to have contained 

 Leach's typical species Phryganea grisea Linn.) is cut off 

 as a distinct subgenus Glyphota^lius, and the true type 

 placed as the twelfth species of the second section. 



The reader will observe that I do not here insist upon the 

 necessity of placing a typical species at the head of a genus, 

 because even our imperfect views of nature will enable us to 

 see that such species ought often more naturally to be placed 

 in company with others not arranged at the head of the 

 genus, but I do insist, that, where an author does not state 

 the particular species which he regards as the type of his 

 genus, we are bound to suppose that he would place it at 

 the head of his genus. 



Mr. Curtis {British Entomology, pi. 632., February, 1837,) 

 has illustrated the genus Pemphredon, giving P. lugubris as 

 the type of the genus, and figuring another species (P. 

 unicolor) ; stating, also, that P. minutus Fab., and tristis V, 

 Lind. (which last he had previously but incorrectly given as 

 synonymous with Psen pallipes Panz. See Shuekard, Foss. H., 

 p. 188. and 227.)? were typical species of his genus Diodontus 

 proposed and figured in pi. 436., April, 1834. In an article 

 upon nomenclature, published in the first series of this Maga- 

 sine, Vol. IX., I selected, amongst others, the genera Pem- 

 phredon and Diodontus (then recently separated from that 



