1896.] 119 



Genus Omalus. 



This is the genus to whicli the name Elainpus, Spin., is now 

 applied. Its most common species is E. auratus, Linn., which abounds 

 everywhere. Mocsary quotes E. bidentulus, Lep. — a similarly coloured 

 insect, but with the sides of the apical segment strongly bisinuate — 

 as British, on the authority of Westwood. I think, however, that 

 Westwood's bidentulus was that of Shuckard, viz., ceneus, Fab. (see 

 note on next species). There is no reason why the true bidentulus 

 should not also be British, but it is not in any of the collections that 

 I have seen. It might easily be passed over for a small auratus. 



O. cceruleus. — The insect so named in the Museum collection, and 

 also by Smith in his own collection and in the Monograph, is not the 

 cceruleus of Dahlbom (see note on next species), but the ceneus of 

 Fabricius. 



O. nitidus. — This is called nitidus in Smith's collection, but ceneus 

 in the Museum. Smith gives ceneus as a synonym of nitidus in hia 

 Monograph. This, and not the last species, is the true cceruleus, Uhb., 

 but its right name, according to Mocsary, is violaceus, Scop. M. du 

 Buysson, however, retains the name cceruleus, Dhb., which will be 

 explained hereafter, no doubt, when he comes to discuss the synonymy. 

 It will be seen, therefore, that Smith has reversed this insect and the 

 last, identifying the true ceneus with cceruleus, and the true cceruleus 

 with ceneus. The two species are very distinct, violaceus, Scop. 

 (= cceruleus, Dhb., ^ Smith's ceneus) having a more coarsely punctured 

 thorax, and a very slight though broad apical incision, while ceneus, 

 Fab. (= ceneus, Dhb., = Smith's cceruleus) has an exceedingly smootlx 

 and shining thorax, and the abdomen strongly notched at its apex. 



Genus Hedycheum. 



The insects embraced under this name in our collections, and in 

 Mr. Smith's Monograph, belong to three distinct genera, viz., Holo- 

 pygci, Dhb., Redychridium, A.b. Buyss., and Hedychritm, Latr. Mocsary, 

 indeed, has re-united the lirst two under the name Holopyga, but on 

 grounds* which, I venture to think, would lead rather to a uniting of 

 Hedychridium with Hedychrum (which he does not propose) than with 

 Holopyya. Du Buysson, however (" Species "), gives quite convincing 

 reasons for keeping them distinct. 



H. lucidulum.—Thh is the only true Hedychrum which is cer- 

 tainly British. It has been correctly determined as lucidulum, Fab., 

 though Scopoli's name nobile is adopted as prior by Mocsary. 



* See Monographia, p. 133. He says that some kinds of true Hedychrum have the unguicular 

 tooth remote from the apex of the claw. 



