October, 1913.] 217 



ON THE LRITISH SPECIES OF BYTHINUS, LEACH. 



BY JAMES EDWARDS, F.E.S. 



B. ruNCTicoLLis, Deiiuy = validus, Aube. 



The Areopagus jmndicoUis of Deuiiy was a BytJmius with strongly 

 puuctured thorax, and, in one sex, incrassate femora ; so much is clear 

 from the works of Denny and Curtis and five contemporary specimens, 

 of which two are males, in the Norwich Museum, whei'e Denny's col- 

 lection went in 1825. Denny thought that the specimens with incrassate 

 femora were females, but we now know that they are males. Aube 

 (Psel. Mon., p. 41, t. 87, fig. 4, 1833) has J5. imncticoUis, Denny, which 

 he characterises by its strongly punctured thorax, the first anteunal 

 joint cylindrical, and the femora in one sex incrassate. On the same 

 page he describes his B. chevroJati, which he distinguishes from pttHC^;- 

 collis, Denny, mainly by reason that the first antennal joint is obtusely 

 p)"oduced within, and his figure (op. cit. t. 87, fig. 3a) bears this out : 

 he gives Arcojjagus puncticollis, Curt. (Brit. Ent., No. 422), as a 

 synonym ; but in arriving at this conclusion he may have been influenced 

 by the figure of the basal joint of the male antenna given on Curtis's 

 plate ; the latter, however, is intended to, and does fairly well, represent 

 that part in B. bulhifer, whilst the coloured figure is a recognisable 

 picture of the male of Denny's puncticoUis. In his " Eevision de la 

 famille des Pselaphiens " (Ann. Soc. Ent. Fr., 1844, p. 129), Aiibe 

 makes his B. cJievroJati, which according to the original description has 

 incrassate femora in one sex, a synonym of his B. puncticoUis, which 

 latter he distinguishes from his B. validns by having the femora simple 

 in both sexes. From this point the B. puncticollis of continental 

 authors, of which the definition has been amplified, has clearly been 

 B. chevrolati, Aube, and not ptmcticollis, Denny, the latter insect being 

 known to them as B. validus, Aube. Dr. Fowler in treating of B. validus 

 (Coleopt. Brit. Isl. Ill, p. 90) says the latter is evidently the jJuncti- 

 collis of Denny, but he does not explain why he uses Aube's name in 

 preference to that given by Denny, which has a priority of nearly 

 twenty years. The B. puncticoUis of continental authors (for which 

 the name chevrolati, Aube, is available), is a species with strongly 

 punctured thorax and simple femora in both sexes, and the male has 

 the first joint of the antennte widened towards the apex, just before 

 which on the inner side there is a short cylindrical truncate projection 

 (peg) similar to that found on the second joint of the male antenna in 

 B. curtisii, a small sharp tooth on the inner side of the front tibiae, and 

 the inner side of the hind tibiae for rather less than the distal half is 



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