353 



right angle or, posteriorly, obtuse, the lateral border lightly convex 

 and furnished with low, rounded, smooth tubercles, the posterior 

 angle rectangular or posteriorly acute and produced, the posterior 

 border straight or lightly concave and, like the anterior border, finely 

 serrate. The pores close to the lateral margin. The dorsal surface finely 

 granular throughout, with a row of larger granules along the hinder 

 border and two rows, much more clearly defined at the posterior end 

 of the body, anterior to the last. The caudal process with convex , 

 lobulate posterior border. The lateral surface granular. The sternal 

 surfaces moderately sulcate, with a spine at the base of each leg. 



Copulatory foot with its distal third directed slightly inwards, the 

 apex ending in two flagella, the inner short, lightly curved, and 

 directed forwards, the outer longer and curved forwards, outwards 

 and upwards; posterior to the terminal flagella there is a third short 

 process on the upper surface of the appendage, directed forwards and 

 slightly upwards. 



Length about 43 mm.; width of 10 th somite 6.5; width of 1 st 4.7, 

 length 2.5. 



This species resembles the following in bearing spines on the sternal 

 surfaces. It differs, however, slightly in colour, in having more robust 

 keels, with posterior angles much less strongly produced, the granu- 

 lation coarser and in the different form of the copulatory foot. 



48. Platyrhachus monticola, sp. n. PI. XX, fig. 10— 10 b . 

 Sumatra: Mount Singalang. A single specimen. 



Colour ; head and tergites reddish brown , the head being paler above ; 

 keels and legs and base of antennas flavous. 



Head and antennœ normal; head with a shallow frontal sulcus. 

 First tergite nearly flat above, very convex at the sides, the anterior 

 and posterior borders convex at the sides and converging to form the 

 small lateral tuberculiform keel. The keels of the 2 nd , 3 rd and 4 th ter- 

 gites projecting forwards and downwards, with margins sublobate. 

 The rest of the keels rather small, depressed, following the slope of 

 the back, with anterior and posterior margins finely serrate. Keels 

 from the 5 th to about the 11 th projecting nearly at right angles; the 

 rest becoming gradually more and more directed backwards, the an- 

 terior angle obtuse but not rounded , the lateral edge sharp and either 



