1917.] ' 23 



ascribed to it. Stephens' insect was violet in colour, the rostrum had 

 a sulcus on each side and a deeper one in the middle (111. Mand., IV, 

 p. 200, 1831 ) , and the elytral interstices were thickly punctured (Manual, 

 p. 263, 1839). These characters are proper to sericeus Herbst, but 

 are not to be found in olivacevs Gyll. B. sericeus is reputed to occur 

 on young shoots of oak, in May and June. Stephens says that his 

 ophthalmicus was found within the metropolitan district, but apparently 

 rare. No British specimens of it are known to exist, and the late 

 Mr. E. A. Waterhouse reported that oj>hthalmicus was represented in 

 the Stephensian collection by a single example of olivaceus Gryll. This 

 circumstance, which is confirmed by Mr. Newbery, has no bearing 

 on the identity of the insect described by Stephens under the name of 

 B. ophthalmicus. 



The following table has been prepared from the insects themselves, 

 and includes Byctiscus and Beporaus. 



1 (22) Length of elytra not more than one-half greater than their width. 



2 (5) Elytra with a little very fine adpressed pubescence at their extreme 



apex, or entirely bare. Hind coxae not reaching outwardly to the 

 metasternal episterna. (Byctiscus.) 



3 (4) Elytra pubescent at the apex, the punctured striae irregular. Upper- 



and iinder-side concolorous hetuleti Fab. 



4 (3) Elytra entirely bare, the striae quite regular. Upper-side bright 



metallic green or coppery, rostrum, under-side, and legs dark blue, 



populi Linn, 



5 (2) Elytra evidently pubescent throughout. 



6 (9) Elytra with irregular, and in parts conflvient, puncturation. (Rhtn- 



CHITE8.) 



7 (8) Rostrum thick, distinctly shorter than the head and thorax together, 



of the same colour as the head. Front of thorax in the male with 

 a horn on each side. Pubescence of the upper-side whitish, and 

 therefore more evident in the dorsal aspect. Length 6-8 mm,... 



auratus Scop. 



8 (7) Rostrum somewhat thin, as long or longer than the head and thorax 



together, violet. Thorax simple in both sexes. Pubescence of the 

 upper-side brownish, and therefore less evident in the dorsal aspect. 

 Leng-th 4-6 mm bacchus Linn, 



9 (6) Elytra with punctured striae or rows of punctm-es. 



10 (13) No scutellary stria, (Involvulus.) 



11 (12) Upper-side bronze or coppery ; ninth stria merging with the tenth at 



its half-length cupreus Linn, 



12 (11) Upper-side blue ; ninth stria reaching the apex coeruleusDe G. 



