174 NATURAL ARRANGEMENT OP INSECTS, 



presents us with the most singular structure of the man- 

 dibles observable in the Formicidce : these organs., which 

 are slender,, are protruded in a curve to a great length, 

 and are at their apex recurved upon each other. We 

 think it probable that this form is merely a modifica- 

 tion of the neuter of the Formica curvidentata ; for, 

 with the exception of the mandibles, both have an iden- 

 tity of organisation,, and exhibit the smallest eyes of any 

 of the group. We may, indeed, here observe generally, 

 that the eyes of the Formicida present greater differ- 

 ences of size and position than we detect in any other 

 natural group of insects, and in several they are totally 

 wanting. Eciton appears also numerous in species, and 

 neuters only do we know, but these are evidently genuine 

 ants. The universally distributed Crematogaster dis- 

 plays a singularly recurved and heart-shaped abdomen, 

 which has its peduncle inserted from above. Myrmica, 

 and a few small cognate forms, are the only ones of 

 this division that occur in Great Britain. The At- 

 tidce, which offer such an enormously developed head 

 in the modification of the neuter individuals, takes a 

 more southern range ; and the genus (Ecodoma, the type 

 of which is the Form, cephalotes, appears to be tropical 

 and American ; but we know allied forms from the east, 

 which,, perhaps, possess equally destructive propensities, 

 and constitute as numerous communities. We must, 

 however, hasten on; for a volume bulkier than the pre- 

 sent would scarcely do justice to all the peculiarities of 

 habits and organisation that we meet with in the For- 

 micidce: but we cannot quit them without noticing the 

 spider-like form of Cryptocerus ; and, indeed,, Lund 

 informs us that its habits and movements as much re- 

 semble those of a spider as does its form. It is com- 

 paratively solitary, although consisting of three indi- 

 viduals; and is usually found upon or beneath leaves, 

 lurking, curled up, ready to spring upon its unwary 

 prey. It derives its name from the structure of the 

 head, which has, on each side, a deep lateral channel ; 

 wherein, in repose, the antennae are inserted and con- 



