■I4^>- 



li. DIPLOPODA, 



The order Diplopoda contains the following families: — Polyxcnidae, 

 Polvzonidae, Glomeridae, Polvdesmidae, Chordeumidae, Lysiopetalidae and 

 lulidae. The first and second of these Latzel places in the suborders 

 Pselaphognatha and Colobognatha respectively. The remaining families 

 constitute the Chilognatha proper. All except the Glomeridae'^- have been 

 reported from North America. The families may be distinguished as 

 follows: 



A. — Body small (2.5 mm. long), soft-skinned, more or less scaly or covered in parts 



by bushy hair; protomakTC without stipes, uncovered; anus in the penultimate 



segment; odoriferous glands wanting; 13 pairs of legs... Rnn. i. Polyxenidae. 



Body covering crustaceous; legs not less than 17 pairs B. 



B. — Head small, triangular; mouth more or less rostrate, thus appearing suctorial; 



protomala; small; deutomalce obsolete or wanting Fam. 2. Polyzonidae. 



Mouth parts masticatory; protomalje large; deutomalce well developed C. 



C. — Body composed of 19 — 20 segments; scuta often projecting laterally, forming 



laminje; legs 28 — 31 pairs; eyes wanting Fam. 3. Polydesmidae. 



Body composed of about 30 segments, frequently setose; legs 40—50 pairs; eyes 



usually distinct Fam. 4. Chordeumidae. 



Body segments indefinite always more than 30 D. 



D. — Body long, slender, tapering; scuta usually deeply furrowed; antenna long, 

 slender, the seventh segment short and conic; legs very long, the eighth pair 



only modified in the (^, the seventh and ninth pairs normal; sterna free 



Fam. 5. Lysiopetalidae. 



Scuta moderately if at all furrowed, carinate or warty ; antennns and legs short 



or only moderately long ; both pairs of legs of seventh segment of (^ modified ; 



sterna at least of anterior segments united so as to form complete rings 



Fam. 6. lulidae. 



* The GlomeridcK of all Myriapods most resemble the pill-bugs or sow-bugs 

 ( OniscAda;) in their general features and habits. They may be distinguished from 

 other Myriapods by their short body composed of 11 — 13 segments, and by having 

 only 17 — 23 pairs of legs. 



