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the other three species of Macrodorcas I am at present unacquainted ; 

 but in the British Museum collection there is a small variety of 

 M. niponensis, having simple mandibles, which so nearly agrees with 

 M. rugipennis (Mots.) as to make it probable that that species is only a 

 variety of M. rectus, described immediately before it. 



Macrodobcas opactjs, sp. nov. 



$ , M. parallelus, depressus, opacus, nigro-fuscus ; capite transverso, 

 deplanato, supra subtilissime granuloso, pone oculos punctis interspersis, 

 antice fere recto-truncato, angulis anticis oblique truncatis, lateribus 

 parallelis ; mandibulis tenuibus, sub-arcuatis, medio intus dente obtuso 

 armatis ; thorace capite latiore, transverso, supra subtilissime granuloso, 

 punctis parvis interspersis, suturd Iceviore parce punctata; scutello basi 

 opaco, punctato ; elytris elongatis, parallelis, apice r&tundatis, opacis, sat 

 crebre at leniter punctulatis, suturd sub elevatd, nitidd, parce punctulatd ; 

 iibiis anticis h-denticulatis, mediis uni-spinosis, posticis inarmatis ; tarsis 

 ciliatis ; mesosterno parce flavo-pubescenti, suturd nitidd, leniter canali- 

 culatd, lateribus reticulato-punctatis ; abdomine sat crebre punctulato, 

 suturd Iceviore. 



Long. corp. (mand. excl.) 9i lin. f20 mill.) 



Long, mandib. 2 lin. ("4 mill.). Habitat, N. Japan (Hakodadi). 



In Mus. Brit. 



This species resembles a very small Macrodorcas niponensis ; but 

 the head is not contracted behind, so that the sides are almost parallel. 

 The thorax is proportionately less broad. The elytra are almost of an 

 equal breadth, from the base to the posterior two-thirds, and are then 

 evenly rounded ; whilst in niponensis the elytra are slightly narrowed 

 at the base, broadest in the middle, and then gradually contracted to 

 the apex ; the humeral angles are slightly produced ; in niponensis the 

 elytra are thickly and finely rugulose-punctate, the interstices being 

 shining ; in opacus the elytra are dull, being somewhat thickly and 

 delicately punctured. The abdomen is distinctly punctured, somewhat 

 thickly so towards the margins, where it is dull ; whilst in niponensis it 

 is sparingly punctured, the sutural portions of the second, third and 

 fourth segments being scarcely punctured at all. The meso-sternum is 

 longitudinally concave. The metasternum in opacus is gently but 

 distinctly canaliculate, especially posteriorly. 



The female is at present unknown. 



British Museum : December 21st, 1869. 



