NOTES ON MILLIPEDES. 5 



Key to Classification of Millipedes. 



I. Body furnished with tufts of scale- like hairs. Antennae 



eight jointed. Scent-glands absent. Sub-class PSELAPHO- 

 GNATHA; contains the single family Polyxenidce, minute 

 millipedes, " only about one tenth of an inch long " 

 (Pocock, R. N. H. vol. vi, p. 209), so far not known from 

 the Malay Peninsula. 



II. Body not furnished with tufts of scale-like hairs. Antennae 

 seven jointed. Scent-glands usually present. Sub-class 

 ClULOGNATHA ; divided into three orders. 



A. Body short and broad, 12 or 13 segments, second and 

 last segments enormously enlarged, capable of being 

 rolled into a ball, no scent-glands. Order Oniscomoepha. 



B. Body elongate, 19 or more segments, none of them very 

 much larger than the rest, capable of being spirally coiled 

 (except Sphooviodesmus). 



A. Last back plate forms a hood over the last pair of 

 legs, 19 or 20 segments, no scent-glands, no known 

 species exceeds a quarter of an inch (6 mm.) in length. 

 Order LlMACOMOKPHA, contains the single family 

 Glomeridesmidte ; a species occues in Sumatra. 



B. Last back plate forms a complete ring, enclosing the 

 anal valves, 19 to over 100 segments, some species 

 exceed 9J inches (say 250 mm. in length). Order 

 Helminthomoepha. 



a' Mandibles degenerate, from about 30 to over 100 

 segments, species seldom exceed 1J inch (38 mm.) in 

 length. Sub-order Colobognatha. 



b' Mandibles normal. 



a". Pedal laminae free, 30 to 32 segments, Sub-order 

 Chordeumoidea. Small Millipedes known from Sumatra, 

 Burmah, etc., but so far not from the Malay Peninsula. 



b". Pedal laminae united to the terga. 



a'". From about 30 to over 70 segments, Sub-order 

 Iuloidea. 



b'". 19 or 20 segments, Suborder P ohjdesmoidea, _ 



