150 THE entomologist's record. 



Cox. — Handbook of BrilUh Coleoptera, H. E. Cox, 1874. 



Fowler. — Colcopteia of the British Islands, W. W. Fowler, vol. 5, 1891. 



The descriptions iu Herbst's and Gyllenhal's works are of very 

 little scientific value. They may have been sufficient when but few 

 species were known, but they are of so loose a character that they will 

 often fit three or four of the now known species. Herbst's types no 

 longer exist, and it is impossible, either from the text or figures, to be 

 at all certain of the species to which this author refers. Gyllenhal's 

 types still exist in the Museum at Stockholm, where also those of 

 Schonherr and Boheman are preserved. Schonherr's work is much 

 better, and the descriptions are often all that can be desired for 

 identifying the species, many of them are written by Gyllenhal or 

 Boheman. Brisout's MononrapJi is a very good one, and I believe it 

 is the latest that has appeared on the genus. I am greatly indebted 

 to Bedel's work for many of the best characters in my table. The 

 author has the faculty of describing dift'eninces in a short but very 

 lucid manner. The works of Cox and Fowler are in the hands of 

 every student and need no commendation from me. 



Habits and foodplakts. — All the species are found on aquatic 

 plants, but we know as little of the habits of these insects as in 

 Brisout's time. Bedel mentions that all the species of which the 

 habits are known live exclusively on monocotyledons. This would 

 appear to be correct, but with the exception of B. binodulins, which is 

 said to be found on Stratoitcx aloides, and B. aliswatis, which feeds on 

 the leaves of Alimia plaiitai/o, nothing is known of the foodplants of 

 the British species. Some are subaquatic, others — miiillaccKn for 

 instance — seem confined to salt or brackish water. All the species 

 simulate death when disturbed, and remain quiescent for a consider- 

 able time. A good plan of capturing the subaquatic species is to rake 

 the water-weed upon a piece of waterproof sheeting, drain oft' the 

 water and shake the weed well. The beetles will fall on the sheet, 

 but will be difticult to see on account of their death-shamming habits 

 and obscure colours. 



Sexual diffeeences. — These are very little marked. The rostrum 

 of the male is shorter and more pubescent than that of the female, 

 with the antennae inserted nearer the apex. The metasternal 

 impressions are also more marked, and the hooks at the apex of the 

 tibiae rather more developed. In the female the rostrum is often bare 

 and impunctate in front of the insertion of the antennje. 



Miscellaneous obsekvations. — The distribution of the genus is 

 peculiar ; omitting the generally distributed alismatis, it will be found 

 that almost all the records are from the south or east of England, or 

 the London district. One species only has occurred in the west, i.e., 

 B. nifjritarsis, at Candleston, Wales. Scotland claims but one species, 

 B. (ilahrmntris, and only one specimen, liitiiln.nifi/, appears to have 

 been found in Ireland. It is extremely probable that the want of 

 attention paid to the genus by collectors is accountable for the limited 

 range of the localities. 



The time of appearance of the perfect insect appears to range from 

 April to October, most of the recorded captures being in the former 

 month. It is almost certain that these insects hibernate. They all 

 vary greatly in size, our largest species is 1>. nodidosHs, the smallest 

 B. lutulosus, though some specimens of B. rlauiiicavn run quite as small. 



