180 ■ [August, 



9 (8). ScutoUum with a distinct central keel, and two pnnctiire:;, which are 



placed just within the side ano^les ; prosternal keel simple, narrow ; 

 pubescence long-, evident, and semi-raised (except in myrmeco- 

 pJiilum, Mots.) Sub-genus Ptenidium, i. sp. 



10 (11). Thorax and elytra coarsely punctured with simple, deep punctures, 



the interspaces being minutely piinctrdate ; thorax with a broad^ 

 impunctate central line ; body black ; antenna; and legs dark 

 yellow Length, 0.8—0.84 mm. P. pundatum, Gyll. 



11 (10). Thorax not coarsely punctiired. 



12 (15). Metasternum smooth, not alutaceotis. 



13 (14). Piody deep black, clothed with long gToy hairs; head and thorax with 



distinct, scattered, shallow umbilicate pimctures, with a central 

 impiuictate line ; elytra with simple piinctures, which are either 

 iiot confluent (type form) or very large, deep, and confliient on 

 apical third (var. rucjnsmn, Britten) ; antennae dark pitch-brown... 

 Length, 0.74 — 0.8 mm. P. fuscicorne, Er. 



14 (13). Body, or at least elytra, castaneous-brown, longish, strongly convex ; 



head and thorax scarcely punctured ; elytra with evident punctures 

 and very short scattered hairs ; antennae yellow. The var. kraatzi, 

 Matth., has the outer basal thoracic fovose deeper than in the type 



form Length, 0.88 — O.Ofi mm. P. myrinecophilum, Mots. 



= formic et or um, Kraatz. 



15 (12). Metasternum alutaceous, at least at the sides. 



16 (17). Thorax, especially at sides, almost as strongly punctured as elytra, 



sides less rounded ; elytra distinctly punctiu-ed in eight or nine 

 irregular longitudinal rows, furnished with long, semi-erect, grey 

 hairs ; antennae yellow, at most with the last two joints slightly 



darker Length , 0.9 — 0.94 mm. P. jjustHitm, Gyll. 



aincale, Erichs. * 



17 (10). Upper-side of thorax scarcely punctured, sides more rounded, inner 



basal foveae less distinct than in pusillum ; elytra more scantily 

 punctured in six or seven irregrdar longitudinal rows ; hairs much 

 shorter and more slender than in pusilluin ; antennte with, first two 

 joints and club nearly always infuscate,^ the midtUe joints being- 

 more slender than those of jmsilliim... 



Length, 0.8—0.9 mm. P. hrisoidi, Matth. 

 = nitidum, Bris., nee Heer. 



18 (1). Transverse fui-rows of scutellum withovit a middle keel, with four 



deep eqviidistant foveae ; prosternal process with two furrows be- 

 tween the anterior coxae Sub-genus Gillmeisterium, Flach. 



Basal thoracic fovea deep, proportional size of outer foveae very 



4 The type of Marsham's /'. evanetce-nn in Stejibens'-s collection i.s AtomaHa punlla, Payk. 

 Gyllenhal's name fpi-.niiiuw) is only a year or two later (ISOS) and should be preferred. 



5 A .specimen in the Matthews collection received from Urisout under the name of iiitUinm, 

 Bris., has i)ale antenna;, but Brisout's description accords with that given above, as do all the 

 specimens we have seen. 



