140 THE MYRIAPODA OF NORTH AMERICA. 



muc 



•h more rigid than in the Chilopods, from the close conjunction, or often imbrication, 

 of the segments, and the inflexibility of the segments themselves, caused by the density 

 and thickness of the scuta and sterna and the absence of lateral membranes. For this 

 reason the Diplopoda possess but little or none of that power of raising and twisting the 

 body, which is so annoying to the collector of tropical Scolopendra. The poorly developed 

 nervous system and organs of special sense, the short weak legs, and the weak muscular 

 and large intestinal development, all point to the vegetable nature of the food of this order 

 and the associated sluggish habits, which indications the total absence of offensive arma- 

 ture confirms. 



M. Brandt (Recueil) divided the Myriapoda into Myriapoda rnanducentia and Mi/ria- 

 2)oda sugentia. The former comprises all those which are provided with mandibles or 

 jaws for seizing or devouring food. The latter, the few centipedes which have the differ- 

 ent pieces about the mouth so united and consolidated as to form a tubule, fitted for the 

 ingestion of liquid food. Although this classification has emanated from such an authority, 

 yet it seems apparent that it does not agree with nature, and must be abandoned. Still, 

 it has seemed to me that in doing this Mr. Newport and others have not allowed these 

 characters the weight that they deserve. Mr. Gray does not even allow them generic 

 force, if his classification (Cyclop. Anat. and Physiol., art. Myriap.) is to be trusted. Or 

 was he entirely ignorant of their existence ! Newport gives to them a family significance. 

 The different structure of the mouth, and the consequent different food and habits of 

 living, although not sufficient to stand in competition with the characters separating the 

 Chilopoda and Diplopoda, are still of higher import than any other differences in the 

 latter order. I have therefore divided the Diplopoda into two suborders, the Chilognatha 

 and Sugentia, retaining old names, but giving new significance to them. The minor cha- 

 racters have seemed to me to confirm this, and to indicate that it is coincident witli the 

 plan on which the Myriapoda have been created. M. Brandt (Recueil, p. 26) divides 

 the Chilopoda. into the Schizotarsia and Holotarsia. These appear to constitute natural 

 sub-orders, and arc consequently here retained as such. 



There lias beeu a great difference of opinion amongst naturalists as to the rank of the 

 Myriapoda, and the position which they occupy amongst the articulata. Mr. Brandt, 

 Gervais, Dana, and others consider them as nothing more than an order of the class In- 

 secta; Le Conte (Class Coleop. N. Am. Introd., p. vii) considers them as a subclass of the 

 class [nsecta; whilst Leach, Latreille, Newport, T. Rymer Jones, &c, grant to them the 

 rank of a class. The latter gentlemen differ, however, as to their position in the zoological 

 plan. Mr. .Newport places them just above the Vermes, and this seems to be their natural 

 po ition. 



I here is doubtless a good deal of resemblance between a hexapod larva and a myriapod, 



