THE SHOET-WIXfJED SCAVEXaEE BEETLi:-. 421 



XLV Lathrobium Grav. 180(i. (Gr.. " hidden + life.") 



iledium or small sized Staphylinids having the prosternum 

 shortened and acute between the front eoxre ; front tarsi strongly di- 

 lated and densely clothed beneath with large whitish pads composed 

 of flattened hairs: fouith joint of maxillary palpi conical and 

 pointed or needle-shaped. 



Casey, in his "Revision," has divided the old genns Lnihrohiuin 

 as recognized by LeConte. Horn and other authorities, into 19 

 genera, ten or eleven of which are probably repn-siiited in Indiana. 

 His distinguishing characters are, in many instances, of minor im- 

 portance and I prefer to rank his genera as groups or subgenera, 

 thus placing all species under the well-lmo'wn name of Latlirohiutn. 

 The follo'fting is a modification cf the key or table of genera as pro- 

 posed by Casey: 



K£Y TO ]XDIAX.\ GEOII'S OR SVBGEXEKA OF LMUKODIVM. 



a. Elj-tra without a fold or i-aise<l line on the deflexed [lortion. 

 h. Neeli broad, lialf. or more than half the width of head. 



c. Hind tarsi li'ii^'t-r and more slender, the biisr.i joint much shorter 



than seudiicl. the fifth much shorter than the first four cnmbinert. 



d. Elytra ver\- slioil. fr(im one-half to t\v<]-thirds the length nf 



thiirax. their bas;il angles obsolete; Inner wings wanting; alj- 



domen rather coaisrly and sparsely punctate. 



Group A. APTEE.\uuii. 

 lid. Elytra varying in length from a little shorter to decidedly longer 

 tlian thorax. Ijasal angles distinct; inner wings present; abdo- 

 men minutely punctate. Group B. Lathkobium. 

 r-c. Hind tarsi shorter and stuuter. the first and second joints suli- 

 eiual, the first four differing but little among themselves and 

 together often but little longer than fifth ; gular sutures parallel 

 and curved, rather widely sejiarated. nearest together near the 

 middle of the surface behind the mouth. 



Group C. LiTHEOEIOilA. 



6&. Xeck narrow, about one-third as wide as head; gular sutures nearly 

 straight, feebly converging behind, nearest together near the base 

 of the head. (ii-ciup D. Tetaetopeus. 



(Id. Elytra with a longitudinal fold or raised line on the deflexed porticm. 

 the line parallel with the side margin. 

 c. First joint of hind tarsi aiual to or slightly louirer than second. 

 f. Four basal joints of hind tarsi subequal ; front tarsi feebly di- 

 lated ; gular sutuies very widely separated, being separated at 

 base liy one-third the width of bend: body very small and slen- 

 der, not over 4 mm. in length. Group E. Pselt)oi_\thea. 

 ff. First and so ■c:nd joints of hind tarsi each longer than the third or 

 fourth. 



