332 Mr. G. Lewis on a 



Dr. Sharp, while writing a memoir on the Japanese and 

 Ceylonese Colydiidce, found twelve of the genera were 

 represented in both collections ; and five species are 

 fomid in Ceylon as well as Japan. And another insect 

 found as yet in Japan alone — Sijmpanotus inctiis, 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 Colydiidce 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- 

 dididce were abundant, but the number of specimens 

 I obtained was small — not abov.e forty altogether. Like 

 Teretrius and Tri/jwnceus, NijJoniKs 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 Nijjonius, 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 Nvponins. 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 



