new Species of HistcriUe. 207 



MaCROUSTER, Lew. Arm. Si M;i;;. Nat. Hist. xiv. 

 p. 145 (1904;. 



Tliis rrenui^, as at j)rcsctit coiistitufi'd, may he coiiveiiitMitly 

 tliviiltnl into two sections. In tlio first, wliicli inclu'lcs the 

 lur;^est spocics, the inc.sosternuni is anteriorly iinn)arginate ; 

 in the second the mar^^inal stria is complete, but there is no 

 intermediate torm, so it is evidently a character ot" some 

 signiticance. 



MucroUster tmarginatus^ sp. n. 



Oblongo-ovatus, convexiuscuhi?, nigcr, nitidus ; stria frontali untice 

 recta utriiKjue anguste iiiterrupta, labro transverse autice oinar- 

 ginato ; pronoto ciliato, etriis lateralibus integris, stria inlerna 

 antice iiiterrupta ; elytris striis 1-3 integris, 4 vage impressa ; 

 pygidio dense punctate ; prustcrno haud striate ; mesustenij 

 eniarginato, stria margiuali late interrupta ; tibiis auticis 

 .'}-dentatis. 



L. 12| mill. 



Oblong-oval, rather convex, black and shining ; the hea I 

 Very finely punctulate, tVontal stria rather tine, straight ante- 

 riorly and narrowly inteirupted an either sido, the labruni 

 transverse an i rather widely eniarginate on the anterioi- 

 edge; the thorax is bistriate laterally and the inner stria is 

 continued anteriorly but is interrupted behind the middle of 

 the neck, lateral edge ciliate ; the elytra, inner humeral stria 

 shortened at the base, not quite touching the oblique stria, 

 1-3 dorsal complete, 4 traceable, punctiform^ and obscurely 

 shortened at the base, 5 indicated apically by three or tour 

 points, sutural wanting ; the propygidium is lightly and 

 somewhat s[)aringly puncture 1 ; the pygidiuni is densely but 

 not coarsely |)unctured ; the prosternum, keel narrow and 

 not striate ; tiie niesosternum markedly eniarginate and only 

 striate on the sides ; the anterior tibi;e are 3-dentate. 



The form ot the labruni is characteristic ot" tiiis species. 



Hub. Bihd, Angola. 



Iltsler marjiuipunctattis, Lew. Ann. & Mag. Nat. Hist. iv. 

 p. 461 (lb7U). 



Of this species only one example is known to me; it is a 

 larger species than J/, ynarf/inatus, Er., but very similar iu 

 its geneial facies, except that the base ot the pruslernal keel 

 is markedly marginate. Eritlison's species has lately been 

 iound commonly in niok-nests, but formerly it was seldom 

 seen, and it was supposed to associate with an ant. The 



