Northern Entomological Society 



5953 



most powerful and generally the largest of the Diptera: they destroy Coleoptera and 

 Hymenoptera, as well as insects of their own class.' Mr. Walker is a good authority, 

 and if we ought to arrange this order, in conformity with the arrangement of 

 the Coleoptera and Lepidoptera, and with that of the vertebrate animals, we now know 

 where to begin ; but it would be just as rational to place a rat at the head of 

 the Mammalia, as a domestic nuisance like the flea at the head of the Diptera. 

 Stephens divides this order into three: 1st, Diptera; 2nd, Homaloptera, containing 

 the families Hippoboscidae and Nycteribidae ; and 3rd, Aphaniptera, the single family 

 Pulicidae. He commences his Diptera with the Culicidfe and concludes with the 

 Muscidae, placing the genus Lonchopteryx at the end. Curtis and Westwood 

 separate only the Pulicidae into a distinct order, boih, however, placing it first, and 

 ending the Diptera with the Homaloptera of McLeay and Stephens. Comparing 

 their arrangements of the order as restricted by Stephens, both commence with 

 the Culicidae the same as he does; Curtis ends with the Phoridse, Westwood with the 

 CEstiidce. In the arrangement of the families and of the genera in the family Mus- 

 cidae our authors widely differ. 



" Neuroptera and Trichoptera. Here Stephens, Curtis and Westwood, agree in 

 making two orders ; but in the British Museum Catalogue these are united under the 

 appellation Neuroptera; the insects constituting the Trichoptera of the above authors, 

 being neither placed first nor yet last. Stephens commences the Neuroptera with the 

 Boreidae and Panorpidee, and concludes with the Perlidae. Curtis begins with the 

 Libellulidae, and ends with the Perlidae. In Westwood's arrangement the Psocidae 

 are the first, and the Raphidiidae the last, of the British families. In the 

 British Museum list, the order including the Trichoptera, is begun with the 

 PsocidiE and terminated with the Perlidae. If we place at the head of the Neu- 

 roptera the most powerful and active of the predaceous insects belonging to it, there 

 can be no diflSculty in the selection ; Curtis is the only one of our authors who places 

 the dragon-flies in that position. 



" Orthoptera. The British species belonging to this order are few in number. They 

 may be divided into five families, and arranged thus : Blattidae, Forficulidae, Ache- 

 tidae, Gryllidae and Locustidae. There are two other families which are not British ; 

 the Mantidae, which are predaceous ; and the Phasmidae, which are probably the 

 lowest group of the order. Curtis separates the Forficulidae and Blattidae, each into 

 distinct orders ; then follow Achetidae, Gryllidae and Locustidae. Stephens and 

 Westwood separate the Forficulidae only. The latter author agrees with Curtis in the 

 arrangement of the families, whilst Stephens nearly reverses it. 



Hemiptera. Stephens begins with the Cimicidae, and ends with the Noto- 

 nectidae. The latter are predaceous insects, and Curtis and Westwood place them at 

 the head of the order : they both terminate it with the Pentatomida) ; but these do 

 not appear to be near the lowest group. 



" Homoplera. Stephens and Westwood place the Cicadidae first and the 

 Coccidae last. Stephens introduces the Thripidae here, which Westwood places in an 

 order by themselves at a great distance from this. Curtis also introduces the 

 Thripidae, but, placing the Homoptera before the Hemiptera, he just reverses the posi- 

 tion of the families, beginning with the lowest group and ending with the highest. 



"Having now taken a cursory review of the commencement and termination 

 of each order, in the adopted methods of arrangement, and seen the great want 

 of some fixed plan applicable to all, let us turn our attention to the relative position 



XVI. o 



