172 [August, 



HYDRJLNA LONQIOR, Ret, and OCTITHEBIUS VIETDIS, Peyron, 

 ADDITIONS TO THE BRITISH LIST OF COLEOPTERA. 



BY E. A. NEWBERT. 



With a view to a short revision of tlie British Palpicorvia T have 

 recently been in corresponrlenoe with M. le Cnjjitnine Sninte Claire 

 Deville, and am p;reat!y indebted to him for much valuable infor- 

 mation and assistance. As a first result of this, T am brinjrinp; 

 forward the two above-named species. It is at |)i'eseut uncertain if 

 they are absolutely new 1o our lists, or whether they should 

 replace HydrcBna anqustata, Sturm, and OchfhehiKS mnrfiipaUens,\ia,tv., 

 respectively. 



T must refer the student to Eey's Palpicornio, 2nd edit., Lyons, 

 1S84, for detailed descriptions of the two species. T propose here 

 only to give such (diameters as will se]iarate them from their near 

 allies. 



HTDii^'^NA LONQTon, Rey. 



This insect comes in the sub-division in which the (dytra have 

 8 or 9 rows of punctures between the suture and the humeral angle. 

 It may be sejiarated from II. riparia, ^^u\i., and niqrita, Germ., by 

 its more parallel and elongate form ; it has, lunvever, considerable 

 resemblance to some forms of riparia, which is on the average a 

 larger insect, with differently formed posterior tibiae in the male. 

 The only species for which //. lonrjior is likely to bo mistaken is 

 11. ancjustaia, Sturm. The following (diaracters will separate these 

 two species : — 



k. — Tliorax very distinctly and rat lior sliavply angled in middle of sides; elytra 

 with stvise regular to apex, interstices narrow ; male witli intermediate 

 tibice lootlied on inner side, and posterior libiae dilated angularly at inner 

 apical third //. longior, Rey. 



AA. — 'J'horax obtusely angled in middle of sides ; elytra with strife less regular, be- 

 coming confused before apex ; interstices less narrow ; male with interme- 

 diate and posterior tibia? simple H. angustaia, Sturm. 



Hydrcena nnqnstata is smaller on the average than H. lonqioj; 

 with the disc of the thorax almost impunctate. M. Ste. Claire 

 Deville has very kindly furnished me with French examples, but I 

 have seen no British specimens. 



If. lonqior lias occurred on several occasions in some of the 

 tributary ditches of the Lymington Kiver, near Brockenhurst. 

 Mr. de la diarde has taken it at Christow, near Exeter, and the 

 specimens from Polmont, (^lasgow, standing as II. anqitstafa in the 

 Power collection must also be I'eferred to H. longior, Rey. 



