D E C A C E R A D E C A P O I) A. 



'245 



most simple and harmless objects with the most fea 

 ful powers. Swammerdam, speaking of this insec 

 says, " I have likewise the small beetle, which bavin 

 firmly and strongly fixed its foremost legs, and bet 

 and put its head through the space between their 

 makes a continued noise in old pieces of wood, wali 

 and ceilings, which is sometimes so loud that upo 

 bearing it people have been persuaded that nocturna 

 hobgoblins, ghosts and fairies wandered about then 

 I think that this may be properly called Sonicephalui 

 or the noisy-headed beetle." Hereon we may observ 

 that Swammerdam's countrymen, the Dutch, do no 

 from his account appear to be so far gone in super 

 stition as the English, by whom this noise is con 

 sidered ominous of death. Thus Gay, in one of hi 

 pastoral dirges, says 



The wether's bell 



Before the drooping flock toll'd forth her knell, 

 Ihe solemn death-watch clicked the hour she died. 



And S\"ift thus satirically alluded to the same insect 



A wood worm, 

 ' That lies in old wood, like a hare in her form, 



With ttcth or with ci:iws it will bite or will scratch, 



And chambermaids christen this v-.nn a Death-watch i 



Hccause, like a watch, it always cries click ; 



'Ihen woe be to those in the hini-e who are sick, 



For sure as a frun they will five- up the ^host, 



If the maggot cries click when it .scratches the post. 



The insect, generally considered as the real death- 

 watch, and of which various figures have been pub- 

 lished in popular works upon natural history, is the 

 Anobium tcsselatum, having the wing-covers of a dark 

 brown colour, spotted with tesselated markings. 

 Tliis species, however, is found in old standing trees ; 

 whereas it is evident that the insect in question must 

 be one which feeds in-doors upon timber worked up 

 into articles of furniture. At the present time (the 

 beginning of July), clicking is to be distinctly heard 

 upon the ceiling and window-frames of houses in the 

 country produced by various specimens of this insect 

 (which we have figured from living specimens), 

 and which is of a much smaller size, and more uniform 

 colour than the preceding, being the Anobium striatum. 

 This noise has been considered to be the call or signal 

 by which the sexes are mutually attracted to each 

 other, and as analogous to the call of birds. The 

 general number of successive distinct strokes is from 

 nine to eleven, given in pretty quick succession, and 

 repeated at uncertain intervals ; and in old houses, 

 where the insects are numerous, they may be heard 

 during the warm weather almost ever}' hour of the 

 day. The noise exactly resembles that made by 

 beating moderately hard with the finger on a table, 

 or rather, we should say, to scratching the top of a 

 chip-box with the point of a pin. Mr. Stackhouse 

 long ago observed the manner in which the noise 

 is produced. The insect raises itself upon its 

 hinder legs, and, with the body somewhat inclined, 

 beats its head with great force and agility against the 

 place on which it stands. On disturbing it, the head 

 is drawn close to the front of the thorax, so as to 

 have the forehead quite perpendicular ; the legs are 

 folded up, and the antennas lodged in recesses 

 between the head and thorax, so as to be quite 

 imperceptible. From these, and other recorded 

 observations, it is evident that, in its perfect state, 

 the insect makes this ticking noise, and also that the 

 noise is produced when (he insect is at large. We 



have, however, more constantly heard the noise in 

 the interior of wood-work, and it has hence ap- 

 peared more than probable that the noise (and it is 

 now frequently to be heard within the wood, when 

 the insects are arriving at their beetle state) is 

 caused by the newly -hatched beetle eating its way 

 through the wood to arrive at the daylight. The 

 metamorphosis of the anobia take place near the 

 surface, the larva taking the precaution of making 

 its way so close to the surface, that only a very little 

 space remains for the perfect anobia to bore 

 through. Hence we infer that the noise is pro- 

 duced by the action of the jaws of the beetle upon 

 the wood, and in this manner only can we account 

 for the fact of the ticking being heard (see Mag. 

 Nat. History, September, 1834) throughout the 

 winter, at a time when the insect is in the larva 

 state, the larva itself also producing the same noise 

 by the similar action of its powerful jaws, in gnawing 

 away the wood, so as to leave but a feeble barrier 

 through which the perfect insect can pierce with 

 facility. Olivier indeed supposes that it is for the 

 purpose of ascertaining the thickness of this barrier 

 that the noise is occasioned. We, however, would 

 refer it to the simple action of gnawing, which, of 

 course, is applicable both to the larva and perfect 

 states. There are not fewer than eleven species of 

 beetles described by Stephens as belonging to the 

 onus Anobium, and it is probable that the majority 

 possess the same powers of making the licking 

 noise above described ; but it is evident that the true 

 death-watch must be that species which resides in 

 old wood furniture, and which we have figured 

 jeneath. 



Death Watch, natural size and magnified. 



There is also another insect common in old wood 

 urniture, books, &c., both sexes of which have the 

 ower of making a ticking noise, but not so loud as 

 he others. This is the Atropos ttgnariut, for an 

 account of which see our article ATKOPOS. 



DECACERA. In the arrangement of modern 

 malacology constituted the second family of the first 

 rder CryptodibrancMata ; first class, Cephalophora, in- 

 luding the genera Loligo and Sepia. 



DECAPODA Ten-legged. An order of crus- 

 aceous animals, comprising all the larger species of 

 ic class, and well characterised in having ten legs ; 

 le head intimately united with the thorax, and covered 

 y a large shell or shield ; a month, consisting of 

 umerous pairs of organs, of which the outer pairs, in 

 ome of the species are elongated ; but the most cha- 

 acteristic trait consists in the existence of gills or 

 ranchia 1 , more or less numerous, fixed in a peculiar 

 avity beneath the sides of the shell. 



This order is divided into two sections, namely, 

 ic Brachyura, having the abdomen shorter than tlie 

 icrax, beneath which it is folded in repose, arid not 

 urnished with a terminal fan-like tail : the common 

 rab is an example of the first section ; and second 

 e Macroura having the abdomen longer than the 



