( 41 ) IV. The genera of Coleoptera studied chronologically (1735-1801) . By G. R. Crotch, M.A. [Read 3rd January, 1870.] Having been engaged for some time in the preparation of a complete list of the genera proposed in Zoology, com-mencing naturally with the Entomological ones, I was very glad to see in the "Proceedings/' a report of the interesting discussion on Mr. Kirby's paper (Proc. Ent. Soc. 1868, p. xlii) . With Mr. Cunning's note (pp. xlv-xlviii) I agree entirely, and it has been suggested to me, that a brief sketch of my work, so far as relates to the Coleoptera, might not be uninteresting. All exact refer-ences, etc., are omitted, to appear in the work itself. A genus appears to me to consist of but one species neces-sarily, viz. its type; round which we arbitrarily group any number of others, which may be removed at pleasure ; it is therefore defined, not so much by characters, which vary with our knowledge, but by the selection of a type-species; from which I argue, that genera proposed in Catalogues, on previously described species, are entitled to priority. It is certainly far less productive of confusion, that a num-ber of genera should be published, as in Dej can's Cata-logue, with their species, than as in Latreille's " Precis," with their characters only. In tracing the types of the various genera, I find that Linnaeus apparently had no idea of types, and that his genera varied considerably in their extent. I have traced them from the first edition of the 8ystema Naturce in 1735, which is, I think, the only consistent starting point, though possibly not the most desirable one ; but certainly Linngeus and his contemporaries "date the introduction of genera from that work, and in the tenth edition he mentions expressly, as a novel feature, that he now intro-duces trivial names also ; (they had, however, been em-ployed for five or six years in his various dissertations, etc.) . It is, nevertheless, unfortunate that he should have changed his opinions as he did. Geoffrey, in 1762, seems to have had a clear conception of types, figuring the typical species always, as did also Scheeffer four years later, adding rough dissections; these authors, therefore, settle most of the Linnaean genera. Fabiicius never TRANS. ENT. SOC. 1870. PART I. (mARCH.)
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