16 coleoptera. 



7. Agabus Erichsoni. 

 A, nigro-ceneus, Erichson, Thorns., nee Marsham. 



The late Dr. Schaum notes (1. c, p. 102) that although 

 the nigro-ceneus of Marsham is not, as Erichson assumed, 

 the species known to the latter by that name, which does not 

 occur in England, but is chalconotus^ it does not seem to 

 him that a change from the name employed by Erichson is 

 necessary. But to adopt this idea would be simply to in- 

 crease confusion, and be at variance with the recognized rule 

 in similar cases. I accordingly propose to give the above 

 name to the German insect; which, as it occurs also in 

 Lapland, will probably be found here eventually. It appears 

 to be closely allied to chalconotus, but to be considerably 

 larger than that species (for which the size is accidentally 

 omitted in Ins. Deutsch.), slightly more convex, delicately 

 s^n^o^e-reticulate, not quite so shining, with the margins of 

 the thorax and elytra lighter, and the underside pitchy, in- 

 stead of black. 



In the male the anterior claws are unequal, the inner one 

 being sub-dentate ; the three basal joints of the hind tarsi are 

 set with swimming-hairs, and the apex of the last ventral 

 segment of the abdomen is longitudinally strigose. In male 

 chalconotus the anterior claws are equal, and only the basal 

 joint of the hind tarsi is set with the swimming-hairs. 



The specimen mentioned by me in Ent. M. Mag., vol. v, 

 p. 46, as nigrO'CeneuSf Marsh., is certainly only a light- 

 coloured var. oi chalconotus. 



In corroboration of Prof. Schaum's verdict that Marsham's 

 nigro-ceneus is only a synonym of the slightly anterior chal- 

 conotus of Panzer, I may (in addition to Mr. Waterhouse's 

 opinion to the same effect recorded in his *' Catalogue ") 

 remark that in my copy of Marsham's Ent. Brit., which is 



