COLEOPTERA. 



133 



a summarised account of two allied hybrids, Biston hybr. pilzii, 

 Standfuss {Ent. Zeits. Guhen., iv., pp. 142-3, v., pp. 109-110; Hand- 

 biich, etc., pi. iii., figs. 1-2), and Nyssia hybr. hunii, Oberthiir {Bull. 

 Soc. Ent. France, 1897, pi. i., ii., and 1900, p. 274, pi. i). The former 

 with the parentage hirtarius $ x pomonarius ? , the latter pomonarius 

 S- X hirtarius $ . The crossing of these allied species, one of which 

 has a winged and the other an apterous female, has produced most 

 interesting results. We are very pleased to know that Mr. Mera has 

 extended our knowledge of the possibilities of hybridisation in this 

 group of Geometrid moths. — Ed.] 



OLEOPTERA. 



Hydrochus nitidicollis, Muls., a species new to Britain. 



By H. St. J. K. DONISTHOEPE, F.Z.S., F.E.S. 



On April 13th last, when searching for Gnypeta coerulea, with Mr. 

 Keys, in the river Meavy, at Yelverton, I noticed a Hydrochus, which 

 I did not recognise. Mr. Keys told me he had never taken a speci- 

 men of that genus there before, and we eventually took four speci- 

 mens. On my return home I found it to be Hydrochus nitidicollis, a 

 species new to Britain. There is a specimen of this species in the 

 general collection of the Natural History Museum, so I was able to 

 confirm my determination of it. It is interesting taking it in running 

 water, as our other four species are all found in stagnant pools, etc. 

 Mr. Keys writes that he has been since I was there, and has taken two 

 more specimens. It is evidently very scarce. The following is a 

 translation of Ganglbauer's description of the insect : " It agrees 

 tolerably, in the shape of the body, with carinatus, from which it is easily 

 distinguished not only by the not (or only slightly stronger) raised third 

 interstices, but also by the less deep and closer together punctures of the 

 strife of the elytra. Above of a lighter or darker bronze colour ; head 

 and thorax often metallic-green, or blue-green ; the elytra often with 

 purple reflection ; the antennae rust-red with blackish club ; the palpi 

 yellow with a black tip to the last joint, or quite dark ; the legs yellow- 

 red or brown-red, the knees and the tips of the tarsal claws, or the 

 whole tibiae and tarsi, black. Head and thorax less deeply, and not so 

 closely, punctured as in carinatus. The thorax about as broad as the 

 head, and about as long as broad, contracted behind, with tolerably 

 deep impressions. The elytra much less punctured than in angustatus, 

 with similar dug-out, punctured stride, the third interstice not, or only 

 slightly, keeled, the fifth, seventh and ninth distinctly raised in blunt 

 keels ; the keels of the seventh almost interrupted by an impression. 

 Length, 2-2mm.-2-5mm. Central and south of France." In two of 

 my specimens the head and thorax are of a beautiful metallic blue- 

 green, and the elytra are purplish, the third, however, is black. In 

 all three the palpi are quite dark. This is a very pretty and interest- 

 ing addition to our list of coleoptera. 



CoLEOPTERA AT YEiiVERTON. — The following species were taken at the 

 same time as the new Hydrochus described above, which will show what 

 a very fine locality this is. Gnypeta coerulea, which was discovered here 

 by Mr. Keys some years ago, Trogophloeus arcuatus, Henicocerus exculp- 



