878 



I NS 



an external ovipositor ; derm-metamorphoses (pupa 

 complete and active, locusts, grasshoppers, mantes, 

 cockroaches). 



B. Mandibles and maxilla; none ; a rostrum, or 

 ort of proboscis, formed of an articulated sheath, in- 

 closing a sucker of four pieces ; elytra (hemelytra) 

 membranous at the extremity in some species ; demi- 

 metamorphoses, except in a few (pupa complete and 

 active), 



Order, Hemlptcra. 

 2. Gymnnptera (naked wings). 

 No elytra, four or two naked wings. 

 A. Four wings. 



a. Upper and lower jaws ; wings generally 

 transparent, not farinose ; tegulae, (scales 

 placed at the base of the upper wings) 

 small and tubercular. 



Order, Ncuroptera, with the 



Wings thickly reticulated ; the posterior of the 

 same size as the anterior, or longer or larger : no 

 cxserted ovipositor in the majority ; no sting, metamor- 

 phoses various. 



Order, Hymcnoptera, with the 

 Wings horizontal, with large areas, or simply veined, 

 the posterior smaller than the anterior ; maxillae often 

 valvular, laterally sheathing the tubular lower lip, and 

 forming a species of rostrum (prornuscis) more or 

 loss elongated ; an cxserted ovipositor, or an anal 

 siing in the majority of the females. 



b. Mandibles rudirnental ; maxillae replaced hy a 

 spiral rostrum (spiritrompe), formed of two 

 fillets, tubular, and rolled up in a spire, united 

 between two labial palpi ; wings farinose, 

 tegnla) (ptcrygodes), large, epaulette-shaped, 

 turned backwards, 



Order, Lcpidoptera (butterflies, moths). 

 B. Two wings. 



Order, Rhipiptera (Mr. Kirby's name, 

 Strep.tiptera, must be retained in- 

 stead of Rhipiptcra}, with 



Two pseudhalteres (prebalanciers), or small crusta- 

 ceous moveable bodies in the shape of small twisted 

 elytra, placed in front of the wings, which are folded 

 fan-wise ; mouth with two setiform pieces, crossed 

 like a pair of mandibles. 



Order, Diptcra, with the 



Wings extended, and accompanied in the majority 

 by two small moveable bodies, in the form of balan- 

 cers, situated behind the wings ; rostrum bent at its 

 base, and generally terminated by two fleshy lips, in- 

 articulate, inclosing a sucker formed of a variable 

 number of sets (flies). 



The first of the above described orders, Aphanip- 

 tera, Kirby, is, in various respects, most nearly allied 

 to the Diptera. It will also be observed that the 

 suctorial Hcmiplera are introduced into the middle of 

 mandibulated insects. 'Ihese difficulties are neces- 

 sarily attendant upon our endeavours to arrange our 

 primary groups in a linear series, in which it is impos- 

 sible to combine all these relations of groups. Thus, 

 it we remove the Hemiptera from the situation as- 

 signed to it by Latreille, and place it amongst the 

 suctorial insects, we shall violate its relations with the 

 Orthoptera, caused by the similarity in its metamor- 

 phosis, and in the structure of the wings. 



Mr. Kirby has further separated the Phryganula: 

 from the Neuroptern, under the name of Trickster a. 

 Mr. Hahday has added another order in the last num- 

 ber ot the Entomological Magazine, named Th^an- 



ECT. 



noptera, formed of the genus Thrips, Linn. M. Laporte 

 has also proposed several other orders in his Etudes 

 Entomologiques. 



The reader will find these various orders treated 

 upon at length in their alphabetical situations. It is 

 here only necessary to observe, that each, according 

 to its extent, is divisible into a greater or less num- 

 ber of groups, and gradually decreasing in value, 

 until our arrival at the families (of which we have 

 spoken more at length under our article CANCEUIDV*:) 

 genera, and species ; the last of which, according to 

 the opinions of some authors, is the only absolute di- 

 vision existing in nature. 



In every extensive genera it has been found ser- 

 viceable to introduce minor divisions, which greatly 

 facilitate the acquisition of knowledge. We have, 

 however, already dwelt upon the nature of these 

 minor groups in our article CANCERID/E, and shall 

 only observe, that in the opinion of some authors (as 

 for instance, Mr. Vigors, in the Zool. Journal) their 

 existence ought not to be admitted ; or if they pre- 

 sent sufficiently distinctive characters, they ought to 

 be regarded as genera, and the next higher group of 

 which they form a part, as sub-families. That the 

 gradual approximation of form in the most extensive 

 groups, where, for instance, it must be admitted that 

 the series, from the number of species, is evidently 

 least unbroken, prevents us from assigning such dis- 

 tinctive limits to our groups, whether of genera (that 

 is speaking theoretically) or sub-genera, as shall com- 

 prise those particular species, in which the characters 

 of distinct genera are blended together, cannot be 

 denied. And the great genus of Caralndte (Fcronia) 

 has frequently been cited. But still even in these 

 kind of groups we find various types of form, which 

 in the typical species of each minor group are so well 

 marked, that if the genus were less numerous in species, 

 entomologists would not hesitate to consider them as so 

 many distinct sub-genera. But by many naturalists 

 the great chain of nature is regarded as formed upon 

 this very mode of confluent characteristics ; and were 

 we to admit, in those most extensive and consequently, 

 as we may well suppose, most perfect series of species, 

 the non-existence of genera or sub-genera, we should 

 be compelled to admit still further, that there is no 

 such thing in nature as any other distinct division 

 than that of species ; and it would be as correct, in 

 such point of view, to assert that a butterfly is a beetle, 

 as it would be to say that a Pcecillus is a Steropus. 

 " It appears to be the opinion of most modern phy- 

 siologists," observe Messrs. Kirby and Spence, " that 

 the series of affinities in nature is a concatenation or 

 continuous series, and that though an hiatus is here 

 and there observable, this has been caused either by 

 the annihilation of some original group or species, in 

 consequence of some great convulsion of nature, or 

 that the objects required to fill it up are still in exist- 

 ence, but have not yet been discovered ; and this 

 opinion is founded upon a dictum of Linnseus's ' JVa- 

 tura saltus non fncif..' If this dictum be literally 

 interpreted, according, to the evident meaning of the 

 word saltus, few will be disposed to object to it, since 

 both observation and analogy combine to prove that 

 there must be a regular approximation of things to 

 each other in the works of God ; and that, could we 

 see the whole according to his original plan, ive should 

 find no violent interval to break up that approxima- 

 tion ; but, if it be contended that in this plan there 

 is no difference in the juxtaposition of the lowest 



