514 MR. F. G. SINCLAIR ON THE [Dec. 3, 



3rd tergite. Lateral margin of keel a straight line, angle rounded, 

 keel with a straight narrow margin. 



4th tergite. Posterior margin of keel distinct ; anterior angle 

 acute, only slightly rounded. 



5th tergite. Anterior angle less acute, first shoulder. 



&th tergite. In this tergite the anterior angle is nearly a right 

 angle. The teeth on the posterior edge of the keels are first 

 distinct on the 11th somite; on the anterior they are not distinct 

 till the 15th. The anal tergite shows four longitudinal ridges, 

 but they are not very distinct ; the two external ones are only a 

 thickening of the margin. The end of the plate is rounded and 

 very indistinctly lobed, edges of anal valves very prominent. 



Sterna smooth, but punctated. The tubercles on the external 

 sides of the bases of the legs have a furrow between them which 

 runs to the base of the keel. 



Plaxyrhacus BJicoARii, var. nov. (Plate XXXI. figs. 35, 36, 

 51, 60.) 



From Tapelung, Patalung State. 



A variety of the species described by Silvestri as beccani from 

 Sumatra. 



There are three specimens of different ages forming an inter- 

 esting series. The oldest is a female, ami measures 85 mm. ; 

 greatest width 11 mm. 



Body narrows somewhat abruptly in front of the 4th somite, 

 more gradually behind. 



Colour black in the middle of the body ; keels, legs, and antenna? 

 yellow ; sterna yellow between the legs, darker under the keels. 



Head granulated ; frontal furrow deep. Space between antennae 

 5 mm. Length of antennae 7 mm. 



1st tergite. Anterior and posterior margins straight ; the anterior 

 with a slight irregularity of the tubercles on the ridge, giving the 

 appearance of a median indentation. Anterior margin with a 

 ridge which is not carried round the edge ; ridge studded with 

 tubercles ; posterior margin straight, with row of nine tubercles, 

 with smaller ones in between. Centre of tergite nearly smooth, 

 more tuberculous near the edge. 



2nd tergite projecting forward and downward, narrow, with 

 row of ten large tubercles on the posterior edge. Lateral margins 

 rounded. 



3rd tergite broader, and not projecting forward and downward 

 so much ; posterior row of tubercles not so marked. Antero- 

 lateral angle of keel acute, but slightly rounded ; postero-lateral 

 obtuse. 



4th tergite hardly points down at all. First beginning of 

 shoulder. 



5th tergite. Shoulder well-marked; anterior angle hardly acute. 



7th tergite. The anterior angle of this tergite is a right angle, 

 and behind this somite the anterior ancrle becomes more obtuse and 

 the posterior more acute. 



