new Species of Histeridse. 275 



the pygidium similarly but rather more evenly punctured; 

 the presternum is bistriate, stria? rather fine, scarcely divergent 

 anteriorly, but widen out a little behind, keel, anterior lobe 

 smooth, a few fine punctures only are seen under the micro- 

 scope; the mesosternum is markedly prominent anteriorly arid 

 has a lateral well-defined marginal stria, but it is not con- 

 tinued along the projection ; the anterior tibiae are 5-dentate. 



This species should be placed close to P. elegans, Lew., 

 both having a very prominent mesosternum, but superficially 

 it resembles P. chalybceus in colour and outline, being in the 

 first character somewhat bluer and in the second somewhat 

 more oval. It is remarkable in having only three dorsal 

 strias. 



Hob. S. Thomas I., Gulf of Guinea (Mocqueri/s, 1900). 

 One example. 



Probolosternus, gen. nov. 



Body oval, rather convex ; head retractile, forehead without 

 a transverse stria, labrum transverse, mandibles acute at the 

 tips ; antenna? inserted below the frontal margin, club oval, 

 and when at rest is received into a fovea under the thoracic 

 angle like that in the genus Pachycrosrus ; the thorax is 

 transverse, arched at the sides, gradually narrowed to the 

 anterior angle, anterior angles somewhat acute, marginal 

 stria extremely fine and not passing behind the head, lateral 

 stria complete close to the edge, leaving only a narrow lateral 

 rim ; the elytra, epipleura? finely striate, the interstice be- 

 tween the inner humeral and first dorsal stria is wide at the 

 base; the propygidium is very large, hexagonal, and convex; 

 the pygidium is also rather large and semicircular in outline 

 behind, but being deflected it is invisible from above ; the 

 presternum, the keel is narrow, bistriate, and incised at the 

 base ; the mesosternum is very prominent anteriorly, and 

 from its base is arched at its sides and is sharply pointed 

 anteriorly where it fits into the base of the narrow prosternal 

 keel, the marginal stria is more or less fine but entire ; the 

 tibise are all dilated, the outer edge of the anterior pair is 

 bowed and multidentate ; the tarsi are short with two claws 

 and the tarsal grooves are nearly straight. The curious form 

 of the mesosternum is shown in fig. 1 (p. 277), which is 

 drawn from an example of P. permundus. 



Probolosternus africanus, sp. n. 



Ovalis, parum convexus, niger, nitidus, supra leviter punctulatus ; 

 elytris striis dorsalibus 1-3 integris, 4 antice interrupta, 5 apicali, 



