ADDENDA 3'33 



by the less coarse punctuation of the elytra, and the fact that the 

 thorax always has the sides less convei'gent behind. From 0. rectangnlus 

 ( = puncticoUis of collections) it may be known by its less elongate elytra, 

 less densely punctured thorax, and the less distinct traces of the basal 

 margin of the latter. 0. brevicollis, with which it has been confused, 

 has a broader thorax, with less punctuation, and sharply marked, 

 almost acute, posterior angles. The length varies from G.r to 

 7^ mm. 



Probably not a great rarity in Southern England. Medway district 

 (Chatham and the Isle of Sheppey) (Walker) ; Bembridge, Isle of 

 Wight (Fowler); Guildford (Champion); ^lickleham (Sharp); Weymouth 

 (J. T. Harris). 



O. championi, Sharp (Ent. Mo. Mag. xlviii. (2 Ser. xxiii.) 1912, 

 209). It seems a little doubtful whether this species is really distinct 

 from 0. riqncoloides, but Dr. Sharp thinks that the characters are 

 sufficient to distinguish it. It has the thorax a little difterent in 

 shape, more scantily punctured, rather less sinuate at the sides, with 

 the hind angles slightly more sharply marked, though really more 

 obtuse ; the a3deagus is shorter and thicker, with a shorter and stouter 

 apical pox'tion. The wings are shorter, more blunt at the tips, with the 

 narrower or the apical portion more obsolete than in any other species 

 (except 0. azitreus, in which they are rudimentary). Guildford (Sharp 

 and Champion) ; four specimens. 



The species is very like large examples of 0. 2}Ci'>'aUehis, but differs 

 by the less distinct basal margin of the thorax, as well as by the 

 slightly different size and punctuation of the latter. 



O. rectangulus, Thoms. (Op. Ent. 1870, 323). This is the species 

 which we regard as common under the name of 0. jmnctlcoUis, but 

 Thomson in 1870 considered that 0. 2)uncticoUis really consisted of two 

 species, and described one of them as new, under the name of 0. 

 rectangulus. Dr. Sharp agrees with Thomson as to their distinctness, 

 and says that we have both uf them in this country. The thorax in 

 O. rectangulus is a good deal narrower than the elytra, and slightly but 

 quite definitely sinuate at the sides, the hind angles being nearly but not 

 quite rectangular. The punctuation of the thorax is rather close, but 

 a good deal more sparing on the disc, and the punctures are not very 

 large, so that in contrast with most of the other species of the genus it 

 might be described as finely punctured. Tiie punctuation of the elytral 

 interstices is always close and moderately fine, and the serial or 

 accessory punctures on the third and fifth interstices are unusually 

 conspicuous and numerous. The pedeagvis is remarkable for the 

 slenderness of its apical portion, which ends as a very definite raised 

 ridge. The size varies fiom 7 to 9 mm., and the colour from pitchy- 

 black to a dark rusty brown, but there is never a strong contrast 

 between the red head and thorax and dark elytra. The thorax varies 

 in length, sinuation of sides, definiteness of the hind angles, and the 

 margination of the base ; the insect, therefore, is difficult to distinguish 



