BELGIUM. 77 



families of the Odonata Fabr., or the genus Libellula of Linnaeus. The arrange- 

 ment given here, and in the previously published Synopsis of the Calopterygini, 

 (which serves to complete the present work), is based chiefly on the veins of the 

 wing. It is a striking illustration of the systematic importance of the characters 

 thence derived, that such are applicable not only to the classification of the 

 Orders and Families in which the ramifications of the veins are few, and their 

 relations simple, but to a case where the multiplication of the secondary veins 

 and the minute subdivision of the network seems at first to present extreme 

 complexity, and a variety without end. It is a subject for keen regret that no 

 general system of nomenclature for the veins and included areolets has yet been 

 established by common consent among Entomologists. It is not merely that a 

 different set of names are in use in respect to the several Orders, but that there is 

 little agreement between the various writers on the same Order. When we 

 compare the terms respectively used by Harris, Jurine, Latreille, Kirby, 

 Meigen, Fallen, De Romand, Lefebure, Herrich-Schseffer, De Selys, Heer, 

 Burmeister, Fieber, Walker, and others, we find ourselves involved in the be- 

 wildering task of acquiring as many distinct dialects almost. It would be a 

 praiseworthy concert of the special votaries of the Hymenoptera, Diptera, Lepi- 

 doptera, Neuroptera, Hemiptera, and Coleoptera severally, to bring all their 

 vocabularies into a common stock, and mutually to sacrifice their private partia- 

 lities to the rule of priority and analogy, where other reasons may seem to fail. 

 But this is a digression. In the present notice we have referred to the genera in 

 the sense in which Dr. Hagen views them, his coadjutor De Selys being disposed 

 rather to elevate to that rank the whole of the twenty-five sub-genera into which 

 he has divided them; and this he has done pretty nearly, in fact, by the mode of 

 nomenclature which he has employed. He avows himself to have been always 

 before opposed to the excessive multiplication of genera ; but a deeper study, as 

 he states, has led him here to change his views. Probably there are few students 

 of Natural History who have concentrated their attention on a single group that 

 have not experienced something of a similar operation of mind in their own 

 case, even while their judgment on the general principle may have remained 

 unaltered, as it applied to other groups, and to the views of other Naturalists. 

 It might be thought that he who has studied a group most thoroughly should be 

 best qualified to appreciate the characters which denote generic distinction 

 therein ; but it may be urged, on the other hand, that one who has a general and 

 more indifferent acquaintance with a large class of natural objects will be likely 

 to judge more impartially of the purpose and the requisites of scientific nomen- 

 clature, framed as it is, or should be, for the very facility of generalization 

 chiefly, whilst a " mononymic nomenclature" even may suffice the student of 

 species and their distinctions. 



Vol. X. A.D. 1855. 

 (Dufour) Belostoma algeriense n. sp., and remarks on the genus ; with a plate — 

 p. 186-198. The remarks chiefly regard the respiratory system, and the structure 

 of the antennas, with the singular cavity in the interior of the eye, in which these 

 organs are lodged. (Lucas) Micipsa n. g. of Coleoptera ; with a plate — p. 294- 

 298. Heteromerous, allied to Tagona ; the single species M. rufitarsis Luc, from 

 the French possessions in Northern Africa. (Perris) History of the Metamor- 

 phosis of various insects ; with two plates — p. 233-280. The species here illustrated 

 are Coleoptera, Liodes castanea, Cryptohypnus riparius, Tarsostenus univittatus, 

 Ebasus albifrons, Agapanthia suturalis, Dircaaa levigata, Sphindus gyllenhallii, 

 Lagria hirta, L. lata, Hispa testacea, Gryphinus piceus, and two Diptera, Ceci- 

 domyia entomophila n. sp., and Platystoma umbrarutn. (Drouet) List of the recent 

 Land and Freshwater Mollusca of continental France — p. 137-185. The species 

 enumerated in this carefully compiled list amount to 220 Pulmonata, 40 Pulmo- 

 branchia, and 35 Pectinibranchia — or 295 Gastropoda in all — and 45 Acephhala. 

 Notes on the characters of various new or obscure species are added, and references 

 to the species heretofore included in the Fauna of France which the author has not 

 been able to determine satisfactorily. (De Koninck) Davidsonia woodwardiana 

 n. sp. ; with a plate— p. 281-287. Davidson's figures of the two other species of 



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