IKTEODUCTIOX. 



nearly related to the Glow-worms, of which the females are 

 grub-like and lethargic, with rudimentary antennae, Avhile the males 

 have these organs of an extraordinarily highly-developed pattern. 

 There is therefore good reason for the conclusion that the sense of 

 smell is one of the principal properties, if not the ojdy one, of the 

 Lamellicorn antenna, and that the more elaborate forms of organ 

 probably indicate the exceptional development of this sense. 



The head is in almost all the Lamellicornia deeply sunk in the 

 thorax in the position of repose, so that the eyes are partly 

 witlulraw n into the prothoracic cavity. In a few, however, the 

 prot borax is so formed tliat the head can be folded beneath it, 

 titting against the projecting front coxa^ and so completely 

 enclosing the mouth and antennae. There are yet others (Acan- 

 THOCEiuNiE) in which the prothorax itself can be folded beneath 

 the abdomen converting the body into a ball, within Mhich the 

 tarsi, as well as the bead-appendages, are enclosed. 



The front part of the head above forms the clypeus, which is 

 usually largely developed and sometimes assumes very peculiar 

 forms. The brow ridge, or canthus, is sometimes very prominent 

 and may be produced backwards, more or less completely 

 surrounding the eye and dividing it into an upper and lower half, 

 or forwards, forming a lateral continuation of the clypeus, to which 

 in the ComiN^: it is united at the edge. 



The organs of the mouth vary enormously in different groups, 

 according to the nature of the food affected. The mandibles of 

 the CoPRiN.E and most of the Cetoniin.*: are soft and incapable 

 of biting, but they are often large and very strong, and in the 

 Stag-beetles (Ll'CA>'id.e) and some others attain an extravagant 

 size in the male. In the Passalid.I:: they are very stout and 

 bear a movable tooth, a remarkable feature not found in any 

 other insect. The maxillae are generally sharp biting organs, but 

 sometimes bear tufts of hair for absorbing and conveying to the 

 mouth the juices which form the insects' food. The palpi of the 

 maxilla) and labium are simple and short, the first consisting 

 generally of four, and the second of three joints. The ligula is 

 well-devtdoped and chitinised in the Lucanid.t: and Passalid^, 

 small and Heshy in most of the Scarab.iim:, and in the groups 

 placed first in the present work reduced to a mere rudiment upon 

 the inner face of the mentum. The mentum is enlarged in various 

 groups inhabiting ants' nests, forming a shield which may coincide 

 with the clypeus and completely concealing the mouth {Criq>(o(h(s, 

 Cosnochilus, &c.). 



Nearly all the Lamellicornia fly freely, although wingless forms 

 occur, occasionally in both sexes but more frequently in the females. 

 These apterous females are, as a rule, rarely seen and many of them 

 are entirely unknown. 



The legs assume a great variety of forms. The tarsi are five- 

 jointed, except in a very few exceptional genera in which only 

 four, or even three, are visible. These are partially degenerate 

 insects livinpr in ants' nests or in some other abnormal enviroinnent. 



