MY in A POD A. 333 



ORDER I. 



MYRIAPODA. 



THE Myriapoda commonly called Centipedes, are the only animals of this 

 class which have more than six feet in their perfect state, and whose 

 abdomen is not distinct from the trunk. Their body, destitute of 

 wings, is composed of a ("usually) numerous suite of annuli, most com- 

 monly equal, each of which, a few of the first excepted, bears two pairs 

 of feet mostly terminated by a single hook; these annuli are either 

 entire or divided into two demi-segmer.ts, each bearing a pair of those 

 organs, and one of them only exhibiting two stigmata. 



The Myriapoda in general resemble little Serpents or Nereides, their 

 feet being closely approximated to each other throughout the whole 

 extent of the body. The form of these organs even extends to the parts 

 / \ of the mouth. The mandibles are bi- articulated and immediately 

 followed by a quadrifid piece in the form of a lip with articulated divisions, 

 resembling little feet, which, from its position, corresponds to the ligula of the 

 Crustacea; next come two pairs of little feet, the second of which, in several, 

 resemble large hooks, that appear to replace the four jaws of the last mentioned 

 animals, or the two jaws as well as the lower lip of Insects : they are a sort of 

 buccal feet. The antennae, two in number, are short, somewhat thicker towards 

 the extremity, or nearly filiform, and composed of seven joints in some; in 

 others they are numerous and setaceous. Their visual organs are usually com- 

 posed of a union of ocelli, and if in others they present a cornea with facets, 

 the lenses are still larger, rounded, and more distinct, in proportion, than those 

 of the eyes of Insects. The stigmata are frequently very small, and their 

 number, owing to that of the annuli, is usually greater than in the latter 

 where it never exceeds eighteen or twenty. The number of these annuli and 

 that of the feet increase with age, a character which also distinguishes the 

 Myriapoda from Insects, the latter always having the number of segments 

 peculiar to them, and all their legs with hooks, or true legs, being developed 

 at once, either at the same epoch or when they pass into their pupa state. The 

 Myriapoda live and increase in size longer than other Insects. 



From this accumulation of facts, we may conclude, that these animals 

 approach the Crustacea and Arachnides on the one hand, and the Insects on 

 the other ; but that as respects the presence, form and direction of the 

 branchiae, they belong to the latter. 



We divide them into two families, perfectly distinct both in their organisa- 

 tion and habits, and forming two genera according to the system of Linna?us. 



