XVI INTRODUCTION. 



Ininiediately below the labiuim are the jaws or mandibles ; they 

 are of various shapes, but are yeiieraily curved and of moderate 

 size ; exceptionally, in the males of certain Lucanidse, they are 

 long and branched, like the antlers of a deer; at other times, as 

 in certain Scarabaiidai, they are very small and partly membran- 

 ous, while in the Platypsyllid^ their presence has not with cer- 

 tainty been detected. 



The motion of the mandibles is always in a horizontal direc- 

 tion, tlie only exception in our fauna being Baianinus, in which, 

 from the position of- the condyles and the structure of the sides 

 of the tip of the rostrum, the motion is vertical. 



The form and structure of the mandibles are of great moment 

 in classitication, and the terms used in the present work are suffi- 

 ciently delinite without further ex})lanation. The mandibles of 

 nearly all Carabidae have a rather broad and deep groove on the 

 outer side, called the mandibular scrobe, near the distal termina- 

 tion of which may often be seen a large puncture bearing an erect 

 seta, corresponding in its nature with those above the eyes. 



In the OtiorhynchidEe the mandibles are provided with a 

 deciduous cusp of varying form and size, which, in most cases, 

 is lost soun after the insect reaches the mature condition. After 

 the disappearance of the cusp its former presence is indicated by 

 a scar, whicli is sometiuies borne, either on the tip of a process, 

 or, more commonly, on the face of the mandible itself. 



Below the mandibles is a second pair of horizontally moving 

 pieces, called maxillse; they are complex in structure, and are 

 of great importance in classification, and therefore demand a 

 special paragrapii. 



Maxillae — The hind portion or base of the maxillas is com- 

 posed of two pieces ; the first articulating with the inner side of 

 the head behind the mentum, is called the cardo or cardinal 

 piece; the second is the xtvpes, articulated, usually, at a more or 

 less acute angle with the first. Attached to the stipes are the 

 appendages, which are normally two lobes and one maxillary 

 palpus; the lobes are varied in form, according to the families 

 and genera, and sometimes one or the other is so small as to be 

 indistinct; the outer lobe is occasionally, as in the Adephagous 

 families, slender, and usually divided into two joints like a palpus, 

 whence in the older books the insects of those families are said to 



