OF THE ORDER COLEOPTERA. ^63 



removes, and chooses another place to work in. When it has 

 completely succeeded in forming a habitation, it sticks at the 

 entrance, by means of the hooks of its tubercles, which an- 

 swer the purpose remarkably well by forming a support, and 

 the insect exactly closes the hole with its broad and flat head, 

 which answers all the purpose of a trap-door. Here the grub 

 remains immoveable, ready to seize the first insect which 

 passes, which is very speedily devoured. Its voracity is 

 enormous, and even its own species do not escape from its 

 devouring jaws. It carries its prey to the bottom of the hole, 

 where it always remains itself, in case of danger. It is easy 

 to observe its manoeuvres by placing it in narrow tubes of 

 glass, but it is rather difficult to be caught. The French 

 naturalists succeeded by introducing a straw or twig into the 

 hole, which acts as a kind of sound, and prevents the sand 

 from falling in and choking up the hole, while the earth or 

 sand around it is very carefully cleared away. The grub 

 was usually found at the bottom of the hole, in a zigzag 

 posture. 



Relative to the systematic arrangement of the Cicindelidae, 

 it may be stated, in addition to the text, that after Manti- 

 cora, M. Eschscholtz has added a new genus Omus ; the 

 characters of which are, that the labrum is transverse, nar- 

 row, bisinuated ; the labial palpi are of an equal length with 

 the maxillary, with the two basal joints short, and the last 

 securiform. The anterior tarsi of the male have the three basal 

 joints transversely dilated, eyes round, and the elytra angu- 

 lated. The only species known is the Omus Californicus. 



The MegacephalcB of the old Continent are apterous, 

 while those of the New World have wings. This distinction 

 has induced MM. Saint Fargeau and Serville to form them 

 into distinct sub-genera ; we will add one from Mexico, 

 which is nearly allied to the Megacephala Carolina, Fahv. 

 This new species we name M. Me.vicana. It is of a brilliant 



