172 staphylinidyB. \_Hijgrunoma. 



in form certain species of Homalota, from which genus it is distinguished 

 by the number of the joints of the tarsi ; it is found in fens and marshy 

 localities. 



K. dimidiata, Grav. Elongate, linear, parallel-sided, depressed, 

 dull black, with at least half the elytra testaceous yellow, the colour being 

 very sharply defined ; head very large, somewhat diamond-shaped, almost 

 broader than thorax, antennae moderately long, pitchy, with base tes- 

 taceous, joints 5-10 somewhat transverse ; thorax fully as long as broad, a 

 little narrower at base than elytra, with a more or less obsolete central 

 channel, very finely and thickly punctured ; elytra scarcely longer than 

 thorax, with the punctuation slightly finer than that of thorax ; hind body 

 almost parallel-sided, finely and thickly punctured throughout, with seg- 

 ments 2-5 plainlyimpressed longitudinally at base; legs reddish testaceous. 

 L. 2^-2 1 mm. 



Male with the dorsal plate of seventh segment of hind body truncate, 

 ventral plate produced ; forehead broadly impressed, and thorax broadly 

 channelled ; female with forehead even, and the thorax finely chan- 

 nelled. 



lu stems of reeds, &c., and at roots of grass in marshy places ; local, but not uncom- 

 mon ; Nortlifleet, Strood, and Lee (Kent); Walton-on-Thames ; Buttersea Fields; 

 Dagenham ; Birchiugton, Ramsgate ; Hastings ; Cambridgeshire and Norfolk fens ; 

 Midland district, Sutton Park, Knowle, Coleshill, Repton, &c. ; Askliam Bog, York ; 

 not recorded from the extreme north of England ; Scotland, very rare, in marshes, 

 Tweed district, " Lurgie Loch," R. Hislop. 



OIiXG-OTA, Mannerheim. 



This genus contains about forty species of very minute insects, the 

 smallest members, perhaps, of the whole family; they are very widely 

 distributed, being found in Europe, North, Central, and South America, 

 Ceylon, Egypt, the Canary Islands, &c. ; they occur in vegetable refuse 

 of various kinds, and occasionally in ants' nests ; the genus is here regarded 

 in its widest sense as including Microcera, Er. {Somatium, Woll.), and 

 the sub-genera of Mulsant and Key : the species are exceedingly hard 

 to determine ; the distinctions rest principally on the number of joints 

 contained in the club of the antennae, but, as in the exotic genus 

 Lamjuria, it is often very difficult to decide with accuracy whether the 

 club is three- or four-jointed, especially if the antennae are at all gummed 

 or not looked at from aright point of view ; the following table must not 

 therefore be depended upon apart from tlie comparative descriptions. 



I. Hind body oblong, parallel-sided or nearly so ; club of 

 autennjE, 4- or 3-jointed ; form narrower. 



i. Club of antennae not abrupt, 4-joiuted 0. INFLATA, lfart?». 



ii. Club of antenna} somewhat abrupt, 3-jointed. 



1. Sixth segment of hind body much longer tluin pre- 

 ceding 0. PABVA, Kr. 



2. Sixth segment of hind body scarcely longer tliau 

 preceding. 



