196 CEToyiix.E. 



impossible, to define its specific limits satisfactorily. Such commou 

 and far-ranging forms tend in particular localities, where they have 

 become to any extent cut off from the main body, to produce 

 geographical races, more or less definitely characterised according 

 to the degree of isolation. The determination whether in such 

 cases a particular form should be called a species or a variety is an 

 arbitrary one and differences of opinion are to be expected. In 

 the present case several such forms may perhaps be distinguished 

 within the Indian area, but larger and more thoroughly repre- 

 sentative collections must be brought together before they can be 

 properly studied. Although I have examined some hundreds of 

 specimens they represent only a very minute portion of the total 

 area of distribution. It is perhaps worthy of notice that in the 

 Northern part of that area the elytra have generally distinct rows 

 of punctures upon the disc, while in the Southern part these are 

 absent (var. viridia'aeus). In some specimens the corrugations at 

 the sides of the pronotum become almost resolved into detached 

 punctures as in the form next described, but as I have seen no 

 completely transitional examples I have treated the latter as a 

 distinct species. 



175. Thaumastopeiis nicobaricus. 



Lomaptera nicobarica, Janson, Cist. Ent. ii, 1877, p. 249. 



Black or very deep blue-black and extremely smooth and shining. 

 The form is very much like that of T. imllus, but is a little broader, 

 more rounded at the sides and more convex above. T\\q jyronotum 

 is distinctly convex, less narrowed in front, and coarsely and not 

 very closely punctured at the sides, without trace of striation. 

 The elytra are rather shorter, less straight-sided, less flattened 

 above and without any lines of punctures. In other respects this 

 is exactly like the preceding species. 



Leivjtli 23-27 mm. ; breadth 12-15 mm. 



NlCOBAU Is. 



Type in coll. Janson. 



176. Thaumastopeiis ceylonicus. 



Thaumastopeus ceyloiiicus, i\ d. Poll* Notes Lojd. Mi/s. xiii, 1801, 

 p. 185. 



Black, very smooth, shining and naked, elongate but not very 

 narrow. The pronotum is not very convex, coarsely, not strigosely, 

 punctured at the sides, with the lateral margins distinctly angu- 

 lated in the middle, and the posterior lobe not very narrow and 

 without a longitudinal impression at the apex. The eh/tra bear 

 several well-marked rows of coarse irregular punctures and are 

 transversely strigose at the sides and apices. The piigidium bears 

 two slight conical prominences and is very finely, deeply and 

 densely strigose, rendering it opaque. The metastemmn and 



