1901. J MYRIAPODA OF THE " SKEAT EXPEDITION." 511 



The third specimen is 87g mm. long and 124-15? mm. brand. 

 Colour dirty brown on dorsal surface, with semicircular patch of 

 pale testaceous colour on the dorsal margin of the last eleven 

 somites (probably due to injury). Legs, antenna?, and sterna are- 

 pale testaceous, with some darker markings on the antennas and 

 legs. 



Platyrhacus marginellus Silvestri. (Plate XXX. figs. 14, 17, 



IS, 20, 22.) 



Prom Grunong Inas, Perak State. 



This is probably the species described by Silvestri, and found in 

 Sumatra; but as his description is very short, it will be better to 

 give a full account of the animal. The specimens are two, a male 

 and a female. The latter is considerably the largest. 



Colour dark brown, almost black, the extreme edges of the keels 

 and of the anal sternite being pale ; the antenna; and legs 

 yellowish brown, but darker than the edges of the keel, probably 

 in the living animal they might answer to Silvestri's description of 

 " rufescentibus." 



Length 52 mm. ; length of antennae about 5 mm. 



mm. 



Breadth of 6th tergite 7g 



15th „ 7" 



„ 17th ,, 6| 



„ 18th „ 5~ 



19th „ 4^ 



Head narrow ; antenna? long ; frontal sulcus deep, extending 

 from between the antennae to the margin of the first somite. 



1st tergite elliptical in shape, the lateral edges of the somite 

 extending considerably beyond the sides of the head. Anterior 

 margin with tuberculate ridge, which extends round a considerable 

 part of the sides of the tergite. A row of tubercles along the 

 posterior margin, and two distinct rows across the middle. 



2nd tergite projects hardly at all forward or downward ; anterior, 

 posterior, and lateral margins distinct; three distinct rows of 

 tubercles. 



The shoulder of the keel quite distiuct on the third somite ; in 

 the ninth the anterior angle is acute, while it is obtuse in the 

 tenth. The pores lie nearly in the middle of the keel and at a 

 considerable distance ([.\ diameters) from the margin. 



Edges of keels with a distinct margin. Posterior margin o£ 

 keels doI dearly serrated before the 15th somite. The posterior 

 angle forms a very short tooth which does not reach the anterior 

 surface of the succeeding keeL The anal sternite is much rounded, 

 and shows little trace of the longitudinal ridges. Sterna smooth. 



The copulatory Eool of the male shows the two claws opposed 

 to one another, one being longer than the other. The copulatorj 

 foot is long and slender. The shape of the body is rather convex, 

 and the keels slightly upturned. 





mm. 



dtl 



i of 1st tergite 4^-5 



55 



2nd „ 6~-6 



55 



3rd „ 6i-7 



55 



4th „ 7-7 



35 



5th „ 7^-8 



