326 STAPHYLiNiD^. [^StenincB.. 



STENIN^. 



The memhers of this sub-family are very distinct by reason of their 

 large prominent eyes, which give the head a sort of hammer-shaped form, 

 and the long slender antennae, which are eleven-jointed, and are termi- 

 nated by a more or less distinctly formed club, and have their insertion 

 quite exposed ; all the coxae are small^ and the posterior pair are widely 

 separated by a bilobed process of the metasternum ; two British genera 

 are contained in the sub-family, Dianoiis and Stenus ; the genus 

 Evcesthetus which has sometimes been included in it is now more cor- 

 rectly referred to a separate sub-family ; there are about a dozen genera 

 altogether in the group ; the curious genus Megalops is now placed by 

 Dr. Sharp near the EvsesthetiuEe. 



Our two genera may be distinguished as follows : — - 



I. Eyes separated from neck by a distinct interval ; hind body 



terminated by two setiform styles Dianotts, Curtis. 



I I. Eyes not separated from neck by a distinct interval ; bind body 



terminated by two very short, almost imperceptible, styles . . Stenus, Latr. 



DXANOUS, Curtis. 



Only two species of this genus are known ; one is found in Central 

 and Northern Europe, and occurs also near Lake Superior, and the other 

 is distributed over a considerable portion of North America ; the species 

 are subaquatic in their habits. 



D. coerulescens, Gyll. Of a deep blue-black colour, which is very 

 bright in life, with a round yellow spot on each elytron ; upper surface 

 shining, with short and not very evident greyish pubescence ; head rather 

 finely and thickly punctured, antennse about as long as head and thorax 

 together, black, with apex sometimes lighter, last three joints forming a 

 very indistinct club ; thorax somewhat cylindrical, more strongly punc- 

 tured than head ; elytra longer than thorax, depressed near suture, rather 

 thickly and somewhat strongly punctured ; hind body narrower than 

 elytra, finely and thickly punctured, with segments 2-4 strongly, and 

 5 feebly impressed longitudinally at base ; legs black, very slightly 

 bluishj tarsi with fourth joint bilobed. L. 5-5| mm. 



Male with the seventh ventral segment of hind body emarginate at 

 apex, leaving the segment of the armature partially exposed. 



In moss in or by the side of swiftly running streams, especially in waterfalls ; often 

 found in company with Stenus Ouynemeri and Quedius auricomus ; local, but not 

 uncommon ; Hastings ; Isle of Wight (abundant in a waterfall on the beach near 

 Ventnor) ; Devonshire, Ilfracombe, Barnstaple, and other localities ; Llangollen, Bar- 

 mouth, and other Welsh localities, especially in mountainous districts ; Cheshire ; 

 Bewdley Forest ; Dove Dale ; Yorkshire j Northumberland, rare, Ouseburn Dene, 

 Wallington, Wooler ; Scotland, widely distributed, Solway, Tweed, Forth, Tay, Dee, 

 and Clyde districts ; it probably occurs in Ireland, but I can find no record. 



