ORTHOPTERA. 211 



omnivorous, they are usually of small dimensions, 

 (Plate VI. fig. 4, mandibles of the house cricket with 

 incisive teeth. Fig. 4 X , one of the mandibles of 

 Acrydium, with a large molar plate near the internal 

 base, b.) 



The organs which next require to be noticed, are 

 the maxillce or under jaws. As they are employed 

 for a similar purpose as the mandibles, they have a 

 corresponding development; they are in fact often 

 of large size, and in their general forms not unlike 

 those of the carnivorous coleoptera. They are always 

 glabrous in this order, or clothed with such short 

 hairs as to be almost imperceptible. The maxillary 

 palpi, (Plate VI. fig. 5, c) are always five-jointed in 

 this order, whereas the normal number among the 

 Coleoptera appears to be four. The portion called 

 the blade of the maxilla, is that which forms the 

 apical extremity ; it is usually incurved and bifid at 

 the tip, (Plate VI. fig. 5, a.) It bears externally a 

 distinct lobe, corresponding to what are frequently 

 described as internal maxillary palpi. The name 

 gaka or helmet is now applied to this piece, (Plate 

 VI. fig. 5, b.) It is frequently palpiform, consisting of 

 two joints, and in some instances, (as in Acrydiurn) 

 apparently of three ; but in all cases it is dilated at 

 the extremity somewhat in the form of a helmet, 

 being vaulted, and covering the apex of the maxillae 

 to which it is usually closely applied. This is an 

 important piece owing to the part it takes in nutrition, 

 and the permanence of its forms in different species. 



The labium or under lip is rather of a more com- 



