COLEOPTERA. RHYNCOPHORA. 327 



very generally distributed, being found in all climates, but mostly 

 abounding in hot countries, as Brazil, &c. ; where the luxuriance of 

 vegetation affords them a plentiful supply of food, the entire family 

 subsisting upon plants ; the perfect insects being often injurious 

 wliere they abound, by boring with their snouts into the buds and 

 leaves of different plants, and feeding upon the interior parts, or 

 the parenchyma ; they are slow in their motions, and being un- 

 provided with any means of defence, and of a timid nature^ seldom 

 quitting the plants upon which they reside, or making use of their 

 wings ; indeed, many species are entirely wingless. The larvoe are 

 white and fleshy grubs, having the body thick, oblong, and arched, 

 and being entirely destitute of legs, the place of which is supplied 

 by fleshy tubercles placed upon the ventral segments ; the head is 

 rounded and scaly, and the jaws strong and liorny, wherewith 

 they are enabled to gnaw the various parts of the vegetables upon 

 which they subsist, and which generally consist of the tender and 

 interior portions of grains and fruits. Very few of these larvte 

 have, however, been observed. Those which have the jaws most ro- 

 bust, attack the harder parts of vegetables ; that of Calandra pal- 

 marum attacking the stem of the palm tree ; others, which have 

 the trophi less robust, subsist upon the farinaceous parts of grains, 

 or the pith of various plants; others feed upon leaves or flowers; 

 some are leaf-miners, and a few reside in galls upon the leaves of 

 various plants. The pupaa are sometimes enclosed in a silken cocoon 

 spun by the larvae, and, during this inactive period of their ex- 

 istence, the rostrum is folded upon the breast. 



These insects are nearly allied, on the one hand, to some of the Hete- 

 romera which have the head rostrated and the tarsi dilated ; and on the 

 other, by means of the Scolytida), to some other wood-boring tribes, 

 especially the Bostrichida^ (Apate, <S:c.); indeed, the resemblance be- 

 tween some of the species of Tomicus, and the smaller Bostrichidic, 

 as Rhyzopertha, is so great, that it is almost impossible without minute 

 examination, to decide to which of the groups some of the species 

 belong. By Latreille, indeed, the Bostrichida? arc made to succeed 

 the Scolytida^ ; whence, by some other Xylophaga, the passage to Tro- 

 gosita, Cucujus, Parandra, and thence to the Longicornes, is supposed 

 to be effected ; but the structure of these intervening groups, and, 

 especially of their larvoe, as I have already shown, clearly proves that 

 this is not a natural transition, and interrupts the series of fleshy apod, 



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