of new Coleoptera from Australia. 199 
Mechidius sexdentatus, sp. nov. 
Oblongus, sat convexus, piceus, rugosus. Capite 
utrinque tridentato. Thorace confertim fortiter rugoso- 
punctato, convexo, lateribus rotundatis, marginibus crenu- 
latis, angulis posticis sat acutis, basi utrinque sat fortiter 
sinuato. Llytris thoracis latitudini equalibus, fortiter 
striato-punctatis, interstitiis irregularibus alternatim sub- 
elevatis nitidis. Tibiis sat latis, fortiter tridentatis; tarsis 
brevibus. 
Long. 33 lin.; lat. 14 lin. 
Head with the margins reflexed, rather deeply trian- 
gularly emarginate in front, the sides with three strong 
triangular blunt teeth. Thorax very coarsely rugosely 
punctured, the intervals shining, the sides rounded in front, 
moderately narrowed behind, the posterior angles are 
moderately acute (but not directed outwards). The 
punctures on the elytra are very strong, and the shining 
tubercles at the base of the punctures encroach upon the 
interstices so as to make them irregular; three of the 
interstices are broader than the others and irregularly 
sub-costiform. The posterior tibiz are enlarged at the 
apex. 
Hab.— Adelaide. 
Mechidius MacLeayanus, Westw. 
Oblongus, subdepressus, nigro-piceus. Capite fortiter 
crebre punctato, antice emarginato, lateribus obliquis 
bisinuatis. Thorace transverso, crebre fortiter punctato, 
antice arcuatim angustato, pone medium paululo angus- 
tato; angulis anticis prominulis obtusis, posticis acutius- 
culis; basi utrinque sinuato. Llytris thorace haud latior- 
ibus, postice paulo ampliatis, striato-punctatis (punctis 
ovatis, singulis basi tuberculo minuto transverso instructis), 
interstitiis alternatis nitidis. 
Long. 44 lin.; lat. 24 lin. 
The anterior margin of the head is not deeply triangu- 
larly emarginate; the sides are oblique, distinctly bisinuate, 
the cheeks rather broad and prominent. The thorax is 
thickly punctured on the disk, but the punctures are not 
crowded; the anterior angles are blunt, the sides are 
gently rounded, more narrowed in front than behind the 
middle; the base is gently sinuate at each side, which 
makes the posterior angles slightly acute. The alternate 
