chamberlin: hyriopoda of the Australian region. 59 



sulcus over about its posterior two thirds, this faintly bifurcate ante- 

 riorly but conspicuously differing from the strong V-shaped impres- 

 sion of, e. g. t pwictifrons. Last ventral plate subtrapeziform, much 

 less strongly narrowed caudad than in pwictifrons, the caudal margin 

 convex, each lateral border incurved near middle and again between 

 middle and caudal end, the region caudad of second emarginations 

 more depressed, densely finely hairy, the second region intermediate, 

 similarly clothed, separated by a depression from the anterior region 

 which is convexly elevated and clothed more sparsely with longer, 

 coarser hairs. Inner aporous hand of coxopleurae broader than in 

 punctifrons, oblanceolate in outline, densely finely hairy; pores of 

 coxopleurae much fewer and larger than in puncHfrqns; no distinct 

 longitudinal sulcus or suture dorsally. Last dorsal plate much broader 

 than in punctifrons, somewhat shield-shaped, the anterior margin 

 being a little concave, the lateral ones convex and converging and the 

 caudal end rounded. The posterior border a lighter area over which 

 are lines suggesting the lines of the palm of the hand or fingers formed 

 by dark chitinous areas arranged in row T s; similar markings along 

 caudal borders of other dorsal plates also occurring. Scutum over 

 genital region with numerous densely arranged dark polygonal areas 

 not arranged in lines. Anal pores present, distinct. 



Pairs of legs, forty-nine. 



Length, up to 45 mm. 



136. Mecistocephalus angustior, sp. nov. 



Type.— M. C. Z. 2,062. Society Islands: Tahiti (W. M. Wheeler). 



Pale ferruginous, the head and prehensors deep ferruginous. Cepha- 

 lic plate 1.87 times wider than long. Differing in form from that of 

 M. punctifrons, being smaller, proportionately narrower anteriorly, 

 so that the sides converge caudally much less strongly; margin widely 

 rounded anteriorly between the ends of the frontal suture, incised 

 mesally between bases of antennae. Puncta absent from frontal 

 region, few elsewhere. Two short parallel furrows in caudal region, 

 these embracing puncta; closer together than their width. Ventral 

 teeth of head close to lateral edge on each side, black, slender and acute. 

 Femuroid of prehensors with two blunt, rounded teeth, a distal one 

 and one proximad of the oblique suture. Claw r and intermediate 

 joints also armed. Anterior ventral plates each with a v-shaped 

 impression in w r hich the side arms are very short; in the middle and 



