New genera and species of Californian Coleoptera

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The word genus, in the present state of entomological science, scarcely admits of " a satisfactory definition, but in general terms may be stated to be an aggregate of species possessing in common a character, or a certain assemblage of characters, considered by its author to be of sufficient stability and persistence to distinguish it as an isolated group. I say "considered by its author," because it is this individuality in the opinion of specialists on the one hand, and our imperfect knowledge of nature on the other, which prevent the assignment of a definite weight or value to the characters Avhich have been adopted in the separation of genera as they at present exist; these in many cases have been founded upon comparatively trivial characters, and more or less on the score of convenience. In fact when the Coleoptera have been exhaustively collected, it will probably be found that all genera are more or less arbitrary divisions, as species must in many cases be discovered with intermediate characters, of whatever nature these may be, showing a gradual progression from one to another. In short, that there is no such thing in nature as a rigorously limited aggregate of species, is, I believe, a widely accepted opinion; therefore all genera must be more or less artificial and instituted primarily in order to secure a natural and systematic arrangement and succession of the species, and incidentally to enable these to be easily identified.

If this be granted there can, in the opinion of the writer, be no valid reason for the rejection of the genus Hemistenus Mots. (Areus Cas.). This is surely an instance where a division on the score of convenience is greatly to be desired, and is at the same time fairly warrantable from structural considerations. That there are a few forms which are intermediate and as it were connecting links between the genera Stenus and Hemistenus, is, as above indicated, no more than mufet be expected, and even with these intermediate forms (which, however, are not very evident in the American fauna), the two genera are apparently much more definite than a multitude of those which already exist, and which are considered well established, especially many of the Harpalinide genera.

III

In the table given on page 285 of the present paper the species designated Homalium fucicola should be read //. akjarum, under which name it haa been described on page 316. The name fucicola has been employed by Kraatz for an Icelandic species which, although placed by Gemminger and Harold as a synonym of the Swedish keviusculum Gyll., may nevertheless prove to be a distinct species.

IV

Polyphylla marginata is not described at present, further investigation being deemed necessary to establish its validity.

EXPLANATION OF THE PLATE.

Fig. 1 — Colusa eximia Cas.

Fig. 2 — Pontomalota opaca Lee.

2 a —Maxilla and maxillary palpus.

2 b — Ligula and labial palpus.

2 c— Mesosternal process.

Fig . 3 — Platyusa sonomce Cas .

3 a — Maxilla and maxillary palpus. 3 b — Ligula and labial palpus.

3 c — Mesosternal process.

Fig. 4 — Bryonomus canescens Mann. — Maxilla and maxillary palpus.

4 a — Labial palpus.

Fig. 5 — Cafius {Remus) decipiens Lee. — Maxilla and maxillary palpus.

5 a — Labial palpus.

Fig. 6 — Phucobius simulator Sharp — Maxilla and maxillary palpus.

6 a — Labial palpus.

Fig. 7 — Orus punctatus Cas. — Pronotum.

7 a — Maxilla and maxillary palpus. 7 b — Ligula and labial palpus.

7 c — Antenna and right mandible.* Fig. 8 — Actidium robustulum Cas.

Fig. 9 — Actidium granulosum Cas.

Fig. 10 — Actidium attenuatum Cas.

Fig. 11 — Euscaphurus saltator Caa. — Head and antenna.

11 a — Maxillary palpus.

11 b — Labial palpus.

*The left mandible has not been examined.

C2C3 New genera and species Ent. of Calif ornian Coleoptera.

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