ORDER COLEOPTERA. 475 



knob, and in many the two sexes differ in this respect. The 

 tongue is entirely covered by the mentum, or incorporated 

 with its anterior face, and the elytra join entirely the whole 

 length of the suture, characters which distinguish these insects 

 from those of the fifth section. 



The family of Anophlognathi, of Mr. Macleay, and some 

 other sub-genera, nearly allied to those of the previous sec- 

 tion, will compose our first division. The hood is thick- 

 ened before, and forms, either alone or with the labrum, a 

 vertical facet in the form of a reversed triangle, the point of 

 which is supported on the mentum. This last piece is some- 

 times nearly ovoid, very downy, with the extremity either 

 round or truncated, and without emargination, sometimes a 

 transversed square, with the middle of the upper edge elon- 

 gated like a simple tooth or emargination. The jaws of some 

 terminate in a coriaceous or membranaceous lobe, very downy, 

 toothless, or with one very small, and situated near the mid- 

 dle of the internal edge ; those of the others are entirely 

 corneous, resembling mandibles either truncated or obtuse, 

 and entire at the end, or else terminated by two or three 

 teeth. 



Those whose mentum is nearly ovoid, and very downy, 

 and whose jaws terminate in a triangular lobe, equally downy, 

 without or with very small teeth, and situated near the 

 middle of the internal edge, form two sub-genera. The 

 sternum has no projection. 



Pachypus, Dej. Geotrupes, Melolontha, Fab. 



The antennae of the males have only eight articulations, 

 the last five of which compose the knob. The mandibles are 

 in the form of very thin leaflets, triangular, elongated, and 

 entirely hidden, as well as the labrum. The terminal lobe 

 of the jaws is very small, scarcely distinct, and toothless. 



