26 CHRYSOMELA SUMATRENSIS. 



disk is more closely punctured, iu other specimens the 

 thorax is more transverse, the sides more thickened and 

 rounded and the punctuation more remote. The elytra 

 also show some diffei-ence in the arrangement and depth 

 of the punctures , scarcely one specimen being alike , but 

 I have no doubt that they all represent but one form. 



Chcdcolampra violaceipeiinis , n. sp. 



Below black. Head, thorax and anterior femora rufous. 

 Elytra violaceous or greenish metallic blue, finely punctate- 

 striate. — Length 2^\^ — 3 lines. 



Head impunctate. Second and third joints of palpi in- 

 crassate, of equal length, 4th joint very short, acute, 

 conical. Antennae black , third joint twice as long as the 

 second one , the intermediate joints slightly dilated at their 

 apex, the antennae extending to more than half the length 

 of the elytra. Thorax transversely convex, the sides much 

 rounded and widened towards the middle, narrowly mar- 

 gined , anterior angles produced in a short tooth , surface 

 impunctate , rufous. Scutellum piceous. Elytra slightly 

 widened at the middle , closely and finely punctate-striate. 

 Posterior portion of the breast, the abdomen and legs 

 black, finely pubescent, the four anterior femora and rest 

 of the underside rufous. Claws appendiculate. 



Three specimens, which have been captured at Alahan 

 pandjang , in the District of Rawas and at Lebong (Su- 

 matra-Expedition). 



Chapuis in his diagnosis of this genus , gives an erro- 

 neous description of the proportionate length of the joints 

 of the maxillary palpi. In C. IS-guttata Fabr. the 3rd and 

 4th joints are equal (the latter is not of double the 

 length); in the present species which is a true Chakolam- 

 pra , the last joint is acute and short and the 2 preceed- 

 ing joints are of equal length, there are however no 

 other structural differences to justify its separation. 



Notes from the Leyden ^Iiiseum, Vol. VI. 



