351 



side, but not horizontal, the upper surface almost following the 

 slope of the dorsal surface ; those of the 5 th and 6 th directed slightly 

 forwards, from the 6 th to the end produced gradually more and 

 more backwards; the anterior borders very lightly convex, the 

 posterior being correspondingly concave, both very finely serrate, the 

 lateral margin very lightly convex or straight and only very lightly 

 lobate, the anterior angle obtusely convex posteriorly, the posterior 

 angle acute and spiniform but not strongly produced. The whole of 

 the upper surface of the body covered with low smooth granulation , with 

 larger granules along the hinder border , and very indistinct traces of two 

 other series in front. The pores situated about 1 a mm. from the side 

 margin. The caudal process with convex, obsoletely lobate posterior bor- 

 der. The lateral surface of the body granular. Sterna with a transverse 

 groove, anteriorly and posteriorly emarginate; not armed with spines. 



cf. More slender than the 9 an d much less convex. Copulatory foot 

 terminating in two slender pointed, curved, processes, of which the 

 inferior curves downwards and backwards and the superior inwards 

 and backwards. 



9 Length about 75 mm.; width in of 10 th segment 12.5; width of 

 1»* segment 6.5; of 2** 9; length of 1<* 3.5. 



46. Platyrhachus weberi, sp. n. PI. XX, fig. 9 — 9 b . 

 Sumatra: Ajer Mantjur. 



Colour: head and antennas black; somites black, keels in front and 

 behind yellowish white, black at the base, the black or brown colour 

 spreading along the middle almost to the lateral margin : legs fuscous, 

 paler at the base. 



Head granular above. Antennœ long. 



First tergite elliptical, nearly flat, about twice as wide as long, 

 with distinct keels directed obliquely upwards and backwards , rugulose 

 above, with an indistinct series of tubercles along the anterior and 

 posterior border. The 2 nd and 3 rd with their keels directed obliquely 

 forwards, the plane of the keels being directed downwards and for- 

 wards , the angles rounded and the margins entire ; keels of 4 th hori- 

 zontal, projecting at right angles to the long axis of the body, its 

 angles rounded and its lateral border lightly emarginate. The keels of 

 the rest situated near the summit of the side, horizontal, from the 



