514 INSECTA. 



varid^ated. All these insects are of small size. When touched, they counterfeit death by lowering thi 

 head, inclosing their antennae, and contracting their feet, remaining in this position for some time. 

 Their movements are in general rather slow ; the species which have wings seldom use them for escape. 

 Their larvse are very injurious, and bear a great resemblance to those of the Scarabaei ; their body, 

 ■which is generally curved, is soft and whitish, with the head and feet brown and scaly; their mandibles 

 are strong; they construct, with Ihe fragment of the materials they have gnawed, a cocoon, in which 

 they change to pupje. Other species take up their abode in old wood-stakes or under stones : in other 

 respects their habits are similar. Such ai'e the general characters of the genus 



Ptinus, Linn. 

 Soine have the front of the body narrower than the abdomen, and the antennae simple or slightly 

 serrated, and at least as long as the body. 



Ptinus, Linn., has the antennae inserted below the ey^, and the body is oblong'. Tliese insects frequent houses, 

 and especially grranaries, and the iminhabited portions of the former. Their larvae devour dried plants, and the 

 prepared dry skins of animals. The antennae of the males are longer than those of the females, and in many 

 species the latter are wingless. Pt. fur, Linn. 



Gibbium, Scop., has the antenna inserted in front of the eyes, and the body is short, nearly globular. Pt.scotias, 

 Pt. sulcatus, Fabr. [This last is the type of Leach's genus Gibbium, having the thorax sulcated.] 



The others have the body either oval or ovoid, or nearly cylindric ; the thorax as broad as the abdomen ; the 

 antennae either uniform and serrated, or pectinated, or terminated by three large joints ; they are also shorter than 

 the body. 

 Ptilinus, Geoff., has the male antennae strongly pectinated, and the female serrated. Pt. pectinicornis, Fabr. 

 Xt/lelinus, Latr., and Ochina, Zeigl., have the antennae simply serrated in both sexes. 



Dorcatoma, Herbst., has the antennae suddenly terminated by three large joints, and only 9-jointed. V. dres- 

 densis, Herbst. 

 Anobium, Fabr., has the antennre also terminated by three large joints, but they are ll-jointed. Many species 



of this genus inhabit the interior of our houses, where they do much 

 injury, in the larva state, by gnawing furniture, books, &c., which they 

 pierce with little round holes, like those made by a fine drill. Their 

 excrement forms the fine white powder observed in the holes of worm- 

 eaten wood. Other larvae feed upon flowers, wafers, collections of birds, 

 insects, &c. The two sexes, when calling each other during the period 

 of their amours, beat with their jaws upon the wood-work on which 

 they are stationed, for a succession of times, mutually replying to each 

 other. This is the cause of the noise, similar to the quickened ticking 

 of a watch, which is often heard [especially in old houses], and whith 

 has received from the superstitious the name of the Death-watch. 

 Anobium striatum, Oliv. {A. pertinax, Fabr.), is of an uniform brownish-black colour, and is very common in houses. 

 A. pertinax, Linn, [derives its specific name from the pertinacity with which it maintains its attempt at deception], 

 preferring, according to De Geer, to suffer death under a slow fire, rather than give the least sign of life. 



The third and last section of the Serricornes, forming also a last tribe— that of the Xylotrogi— is 

 distinguished, as above stated, from the two preceding sections, by having the head entirely free, and 

 is composed of the genus Lyme.rylon, Fabr., which we thus divide : — 



Some have the maxillary palpi much longer ; the labial pendent and brush-like in the males, terminated by a 

 large ovoid joint in the females ; the antenna are short, and slightly thickened at the middle. 



Atractocerus, Palis de Beauv., has the elytra very minute; the antennae compressed, sub- fusiform ; the thorax 

 square, and the abdomen depressed. A. necydaloides. Pal. Guinea. 



Hylecoctus, Latr., has the elytra nearly as long as the abdomen, the antennae compressed, and the thorax nearly 

 square. //. dermestoides, Linn. Inhabits Germany, England, and the north of Europe. 



Lymexylon, Fabr., differs from the last in having the antenna; simple and sub-moniliform, and the thorax nearly 

 cylindrical. L. navale, Fabr. This insect is very common in the oak forests of the north of Europe, but rare in 

 the neighbourhood of Paris [and in England]. Its larva is very long, almost like a Filaria. Some time ago, it 

 multiplied to such an extent in the dock-yards at Toulon that the injuries it committed in the wood-works were 

 very great. 



The others have the maxillary palpi very short, and alike in both sexes. The antennae are always simple, and of 

 equal thickness throughout. 



Cupes, Fabr., has the antennae composed' of nearly cylindrical joints, and the penultimate joint of the tarsi is 

 bilobed. C. capitafa, Fabr. North America. 



Rhysodes, Latr., has the antenna; moniliform, and all the joints of the tarsi are entire. R. exaratus, Dalm. Not- 

 withstanding the number of joints in the tarsi, this genus approaches Cucujus and certain Brenti with a short 

 rostrum in both sexes. Their habits are similar to those of the Xylophagi. 



