Myriapoda of West Africa 29 



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clypeus is coarsely rugose over its entire surface, on each side just mesad of 

 the antennae a deep, irregular excavation, and on each .side ahout half-way 

 between the antennse aiid the labrum a crescent-shaped excavation, witli tlie 

 concave side towards the antenna. Upper row of four punctatious, sometimes 

 nearly obsolete or reduced to three ; lower row of punctations consisting of 

 from three to nine on each side of the emargination, and from none to eight 

 behind it. 



Labrum with a shallow or deep emargination ; teeth usually three, occa- 

 sionally two or one, or nearly obsolete, either broad and truncately blunt, or 

 narrower and rather sharp-pointed. 



Eyes triangular in shape, the upper and exterior edges convex outwardly, 

 the lower concave ; the usual arrangement of the ocelli is 12-|- H + 10 + ^ 4" 

 7 4-5+2 = 56, which order is varied to 11 4- 10 + 9 -f 8 + (i -f 3 -|- 2 = 49 or 

 12 +11 +10 + 9+8 + 6 + 2 = 58, or 13 +12 +11+10 + 9 + 7 + 5 + 2 = 69 ; 

 eyes distant from each other by about two-thirds of the transverse diameter 

 of an eye. 



Antennse, with tiie second joint longest, the others gradually decreasing in 

 length; first and second joints smooth oi- with sparse hairs, the other joints 

 increasingly hirsute to the end ; length 8-9 mm. ; if held parallel to each 

 other they scarcely attain tlie third segment ; no disparity in length between 

 the sexes. 



Mandibulary stipe with the exposed sui-face nearly plane, subquadrate, 

 provided with a raised margin ; anterior inferior angle sometimes produced. 



Masticatory plate about twice as long as broad, triangular, surrounded by 

 a raised edge ; near and parallel to its broad end a transverse ridge separates 

 it into two unequal parts, the smaller of which is a deep groove not beset with 

 the short spines common on the remainder of tlie surface. 



Mandibulary tooth oblong, about three times as long as broad, the end 

 rounded, obtuse. 



Dentate lamellse with four or live blunt teeth ; the incisions between are 

 sometimes so slight as to make the margin of the lamella scarcely uneven. 



Pectinate lamellae of eleven more or less complete rows of broad, blunt, 

 curved spines. 



Hypostoma arcuate, the infei'ior surface without longitudinal striae, anterior 

 margin in male broadly emarginate, in female straight or slightly concave 

 medianly. 



Mentum trapezoidal, in the lemale six times broader than long, in the male 

 nine times, the part posterior to the stipe being apparently modified into a 

 large secondary cardo. 



Promentum without bristles,, the anterior margin sometimes nearly straight 

 with a rather abrupt median protuberance, or convex, with a smaller pro- 

 tuberance. In the male the ventral surface of the promentum has the ante- 

 rior two-thirds of its area concave ; in the female this depression is more pro- 

 nounced, and is separated from the level posterior area by a well-defined edge. 

 Stipe with three or four large bristles on tlie anterior margin, and a row 

 along the anterior half or two-thirds of the lateral edge, and a small bristly 



