APPENDIX. 77 



Atlantic islands, the present Megartlirus may be known by being 

 relatively shorter, broader and more ovate, more expanded and con- 

 cave at the sides, and rather more convex down its central region, 

 somewhat paler (or more piceous), more coarsely punctured (espe- 

 cially on the elytra), and not quite so opake. Its head is wider, 

 and deeply branded with a nearly semicircular line (the two ends of 

 which cut into the upper surface of the clypeus immediately behind 

 the base of each antenna, at the exact spot occupied by the open 

 fissure which is so conspicuous in Metopsia} ; its prothorax is also 

 broader, free from a transverse central impression behind, and with 

 the edges (which are minutely serrated, and have the usual exca- 

 vation at the posterior angles) shaped out into a distinct angular 

 tooth immediately behind each of the anterior angles, which are 

 themselves rounded and obtuse ; its scutellum is wide and triangular, 

 instead of being scutiform ; and its elytra are more abbreviated. 



