106 



BRITISH MOTHS 



Another great difficulty which opposes oiir obtaining a natural arrangement of the present family, originates 

 in the diversities exhibited by the caterpillars, and which here appear to assume but a secondary importance. 

 In the Sphingidfe and Geometridffi, for instance, we find the larva state affording the best characteristic of the 

 family ; but here the case is different. Plusia is, in effect, in its imago state as truly a good type of the 

 family, as Polia, Miselia, Acronycta, or Agrotis, and yet the larva; of all these genera are strikingly distinct ; 

 some being Geometrideous, others Arctiideous, and others Noctuideous, if we consider the latter to be charac- 

 terised by a naked fleshy larva, without inequalities on the surface of the body, and with sixteen feet. Of 

 these, many are radicivorous, but they are easily distinguished from the Hepialideous larv:e, although the 

 resemblance between the latter and those of Gortyna is very close. Some of these naked larvae are external 

 feeders, and have the body more coloured, and others have the eleventh segment of the body more or less 

 angulated above. Acronycta varies in its larvaj, (thus at once affording an instance of the difficulty of forming 

 a true estimate of the value of the character of the preparatory states in these insects,) being strongly hairy in 

 A. Menyanthidis, and having an elevated horn near the extremity of the body in some of the other species. 

 That of Dipthera Orion nearly resembles that of an Arctia, whilst Ophiusa has a naked larva greatly attenuated 

 at each end, and Thyatira also a naked one, but furnished with a number of conical tubercles throughout the 

 ■whole length of the body. Those of Catocala are strongly fimbriated at the sides of the body ; in Acosmetia 

 there are only six ventral feet, whilst in Plusia and Euclidia, which have semi-geometrical larva:, there are only 

 two pairs of ventral feet. Those of the last-named genus are quite vermiform in their appearance, and have the 

 habit of twisting themselves about in all directions. 



As the classification of the groups of this extensive family has recently attracted considerable attention on 

 the Continent, it will be useful to give a short account of the different arrangements which have been proposed. 

 Latreille, after separating the exotic genus Erebus (in which the wings are always extended and horizontal, and 

 the last joint of the palpi long and naked, and which comprises some of the most gigantic insects in the order,) 

 proposes to divide the remainder into two extensive and parallel series. In the first the larvcB are geometrical 

 in their mode of progression, some having sixteen feet, but with the two or four anterior ventral feet shorter 

 than the others ; and the others have only twelve feet. The second series comprises "the genera Calyptra, 

 Cucullia, Xylina, &c., all of which have sixteen feet, the anterior ventral ones being of the ordinary size, and 

 their progression is not geometric. Ciirysoptora concha in the former series, and Erastria in the latter, appear 

 equally to lead to the Pyralides. Catocala, Ophiusa, and Brepha, on tlie other hand, appear most nearly allied 

 to Erebus. Mr. Stephens has adopted an arrangement which differs materially from those of Ochsenheimer and 

 his followers, who he considers have placed several of the genera in unnatural situations ; he has therefore 

 attempted to arrange them in a continuous series, somewhat in accordance with their transformations, com- 

 mencing with TripliMna, Agrotis and some allied groups, which he separates therefrom. 



Dr. Boisduval in his new work (Genera et Index Methodicus Europ. Lepid. 1840,) has separated the 

 Noctuaj into fourteen tribes, mostly named after the leading genus in each. They are as follows: — 1. Noctuo- 

 Bombycini (Cymatophora, &c.) 2. Bombycoides (Acronycta, Bryophila, &c.) 3.* Amphipyrides (Amphipyra, 

 Scotophila, Rusina, &c.) 4. Noctuides (Segotia, Cerigo, TripliEena, Agrotis, &c.) 5. Iladenides (Apamea, 

 Hadena, Sliselia, Polia, &c.) 6. Leucanides (Iilythimna, Leucania, Nonagria). 7- Caradrinides (Cara- 

 drina, &c.) 8. Orthosides (Orthosia, Cosmia, Xanthia, &c.) 9. Xylinides (Xylina, Xylocampa, Cucullia, &c.) 

 10. Plusides (Abrostola, Plusia, &c.) 11. Ileliothidcs (Anarta, Ileliothis, &c.) 12. Acontides (Acontia.) 



• This and all the following tribes arc erroneously numbered by Boisduval. 



