111. On a new genus of Histeridae. By GEORGE LEWIS, F.L.S.

[ R e d February 4th, 1885.1

PLATE VIII. I FOUND a genus of Coleoptera in Japan whose members deviate so far from the Histeride in their general struc- ture that, after a careful examination of their characters, I excluded it from a paper on this family in the ‘ Annals and Magazine of Natural History,’ February, 1884, and merely alluded to it on pagz 137 as probably belonging to the Syiateliide. A more perfect scrutiny of the insects convinces me, however, that they are true Histerids, although their location in the family is not easy to determine. There is much that is abnormal in their structure. If the elytral striae and general surface sculpture is considered important, they may be placed near the cylindrical species of Platysoma; but there is no lip or chin to the prosternum, and, if this is thought to be an essential character, the genus must be put near Tryponeus. I am inclined myself to set them in the catalogue after Platysoma, because they are allied to the latter genus in their habit of life and mode of seeking their prey, rather than to Teretrius or Tryponeus.

The genus rests even now on four well-marked species, and two of these have a large range over Japan and occur in localities whose extreme limits lie 700 miles apart; we may rest therefore on the assurance that a genus so widely distributed is not confined to Japan alone, for although it is true the beetles from having a definite habitat are inclined to be local, they also belong to a class likely to be conveyed long distances in floating timber. In August, 1880, I saw large oak- trees on the beach at Horobetau,-strewed there by a gale in the Pacific,-and trunks of such size doubtless landed large numbers of insects on the sea-border of Southern Yezo. But there are more weighty rea,Bons for the supposition of a, wide distribution. Lately

T U N S . ENT. 800. LOND. 1885.-PART 11. (AUG.)

332 Mr. G. Lewis on a

Dr. Sharp, while writing a memoir on the Japanese and Ceylonese Colydiidm, found twelve of the genera were represented in both collections; and five species are found in Ceylon as well as Japan. And another insect found as yet in Japan alone-Sympaaotus pi~tus, Sharp, -is closely allied to Coxelus guttulatus, Leconte, and in coloration agrees with it spot for spot. Thus small entomophagous Coleoptera living under bark or in rotten timber, as Colydiidm do, are exposed to conditions which are in a great part the same all the world over ; and we find them agreeing inter se more than those kinds that in the imago-state lead an active, and there- fore a more diversified, life, rather than one in which concealment is continually courted.

My captures were made in moist forest-lands where such insects as Cucujus, Hololepta, and many Niti- dulidm were abundant, but the number of specimens I obtained was small-not above forty altogether. Like Teretrius and !l'r!jponmus, Niponius is entomophagous, and essentially diurnal ; but instead of following the Platypi, which bore diametrically into the timber, it seeks out Scolyti and Tomici, which reside either in the bark or not far from the cambium. In fine weather in June, at Kashiwagi, I have taken Niponius, in company with Cyphagogus, crawling over the bark of oaks in search of fresh burrows.

There are other Coleoptera which have something in common with Niponitis. Osorius and Nemosoma, for instance, have the armature of the head formed on a similar plan, and there is a certain correspondence in their habits. These usually live in old trees, and, when seeking food, force themselves through galleries partially obstructed by frass or fragments of wood, or burrow for their pabulum in the wood-mould created by decay under the bark; but in Osorius there are stercoraceous as well as arboreous species both in Japan and Ceylon, and it is only the latter which have the epistoma cornute. These facts taken together are evidence that habit, or the mode of life of an insect, precedes structure, and in these genera is the primary cause of the arrangement of the organic elements which build up the frontal formation we see in the species named. But, when stating that habit is sufficient to account for the manner of their construction, we must not forget that when a structure is once set up, modification of habit and modification of

new genus of H i s t e d e . 333

structure advance together, and act reciprocally one on the other.

NIPONIUS,* n. g. Corpus elongatum, cylindricum, nitidum. Caput magnum non

retractile, epistomo cornuto ; mandibulis validibus reflexis, biden- tatis. Antennis elongatis, ante oculis insertis, clava ovali 4-articu- lata, 8' obsoleto. Pronotum parallelum, punctatum caput longium utrinque marginatum, scutellum minutissimum. Prosternum angustatum marginatum, lob0 antico nullo. Elytris tenuis striatis. Pygidium foveolatum. Meso- et metasternum canaliculatis. Pedes sat elongatis, tibiis extus basali dente armatis.

Niponius impressicollis, n. a. (Pl. VIII., figs. 1-11). Cylindricus, sat elongatus, robustus, niger, punctatus. Antennis

pedibusque, nigro-piceis, clava tarsisque rufis ; epistomo cornuto, piceo, transversim bicarinato, thorace grosse punctato, utrinque profunde impresso. Elytris striis 1' validis et cteteris puncti- formibus vel obsoletis. Propygidio quadri foveolato. Pygidio pro- funde bisulcato. Long. 6-5+ m.

This species is t,he largest and most robust of the series, and is distinguished from the others by the depth of the impressions in the thorax. I obtained eighteen specimens ; gathered in pairs or single examples, from localities ranging from Yuyama in Higo to Junsai in Yezo.

Niponius osorioceps, n. 8. (Pl. VIII., figs. 12-14). Cylindricus, elongatus, niger, punctatus, pedibus nigro-brunneis,

epistomo piceo transversim tricarinato, thorace grosse punctato utrinque obsolete impresso, elytris striis N. impressicollis simil- limis. Propygidio pygidioque profunde bifoveolatis. Long. 43 mm.

This insect is less robust than the last; the chief specific differences lie in the sculpture of the propy- gidium. Only two examples were captured, both in Higo, one at Yuyama and the other at Konose.

.

Niponiusficrcatus, n. 8. (PI. VIII., figs. 15-19). Cylindricus, angustatus, niger, punctatus, antennis, pedibusque

piceis, thorace grosse punctato, sine fovea, propygidio quadrisulcato pygidio biimpresso. Long. 4a mm.

1: The name of this genus is derived from the word Nipon, of which Japan is a corruption.

334 Mr. G. Lewis on a

The narrow form of this species, the divergent direc- tion of the projections on the epistoma, and the different form of the abdominal sulci separate it from the others.

There are five specimens in my cabinet from Yuyama.

Niponius obtusiceps, n. s. (Pl. VIII., figs. 20-23). Cylindricus, elongatus, brunneus, punctatus. Antennis pedi-

busque r d s , epistomo obtuso subfurcato, thorace grosse necnon minute punctato. Elytris fasciis transversis medio nigris. Propy- gidio punctato, pygidio bisulcato. Long. 4 mm.

The colour separates this from all the others, and it is also remarkable in having the propygidium without fova or sulci. The large thoracic punctures also are interspersed with some of a fine grade which is peculiar to it. The elytral stria are almost alike in all the species, and are not consequently of use as discrimi- nating characters.

One example was taken at Oyayama near Kumamoto in Higo, and eight others have come to me through a collector I sent to the Ishikari River in Yezo in 1883.

new genw of Histeride. 936

EXPLANATION OF PLATE VIII.

FIQ. 1. Nipomius impresaicollia. 2. 1 Y

3. 9 1

4. I 9

5. 9 1

7. 9 ,

a. 1 ,

9. 9 ,

10. 3 ,

11. 1,

12. Niponius oaorioceps. 13. 1 9

14. 3 ,

15. Niponiua furcatus. 16. 9 9

17. 9 ,

la. 1 ,

19. ,, 20. Niponius obtusicepa. 21. 11

22. 11

23. 1,

6. ,1

under side. mandible. labrum and lingua. mentum. maxilla. clypeus and labrum detached. antenna. profile. fore leg. hind leg.

profile. face.

profile. face. middle leg. hind leg.

profile. face. fore leg.

Figs. 2-7 are from dissections and drawings kindly provided by The under side of the thorax in fig. 2 is the Rev. A. Matthews.

drawn as if pushed back from the abdomen.