NEW BRITISH SPECIES, ETC., IN 18G6. 77 



of Bui'ton-on-Trent, in August, 1864, on the banks of the 

 Trent at Egginton, while waiting the arrival of Mr. Gurneys 

 and myself, intent on catching Aphtliona nigriceps. Think- 

 ing his insect to be only Elmis Volkmari, Mr. Harris made 

 no remark of his capture ; and it was Mr. Crotch, acciden- 

 tally visiting him, who discovered the existence of this prize. 

 The insect is like an elongate E. Volkmarij with two tuber- 

 cles near the base of the thorax, and two more, in the shape 

 of elongate ridges, on the elytra, near the scutellum. 



This rare insect is described as living in pools connected 

 with rivers, on stones overgrown with Confervce, and wood 

 lying in the water ; also on timber weirs, posts, and hurdle- 

 work in rivers, on floating or submerged pieces of wood col- 

 lected by the dammings of rivers, and (in May and June) on 

 half-rotten willow boughs sunk in brooks. 



52. Elmis (Limnius) troglodytes, Gyll. (Dej. Cat. 



Elonis), Ins. Suec. iv, 395, 1—2; id. ii, xviii, 1 — 2 

 {tuherculatus), G. R. Crotch, Cat. Brit. Col. ed. 2. 

 Mr. Crotch (loc. cit.) states that this species is very closely 

 allied to L. tuberculatus, but markedly smaller, with the 

 thorax longer, and the elytra more visibly punctuate-striate- 

 He has hitherto only seen it from the north. According to 

 Erichson (Ins. Deutschl. iii, 524) the thorax is shorter, with 

 the longitudinal striae not waved, and the space between 

 them more distinctly punctured ; and the punctured rows of 

 the elytra arejiner, 



53. Hydr^na palustris, Er., Col. March, i, 200, 1 ; 



Kies., Linn. Ent. iv, 167; G. R. Crotch, Cat. Brit. 

 Col. ed. 2; id. Proc. Ent. Soc. 19 Nov. 1866. 

 Hydrcena 2 nov. Sp. ? Wat. Cat. 

 Taken in the north of England by Dr. Power and Rev. 



