chamberlin: mykiopoda of the Australian region. 61 



dentiform than the others. The median piece of labrum is caudally 

 much narrowed, the lateral pieces touching, or nearly so, ventrad of 



its apex. The mandible hears nine laminae which are dentate through- 

 out, with the distal teeth longer than the proximal ones excepting on 

 the first lamina which hears six teeth differing hut little in length. 

 Cephalic plate near 1.8 times longer than wide. The sternal sulcus 

 bifurcate anteriorly, the angle of the fork rectangular or nearly so. 

 Coxopleurae of the usual general type with numerous small pores. 

 Head and prehensorial segment chestnut, the body brown with ohseure 

 dusky mottlings. Young specimens show a greenish tinge posteriorly. 



Pairs of legs, forty-nine. 



Length of type, 84 mm.; greatest width, 3.2 mm. 



139. Mecistocephalus simplex, sp. nov. 



Type.— M. C. Z. 2,067. Queensland: Cairns (W. M. Wheeler). 



Superficially this species differs from the preceding one, M. kuran- 

 danus, in having the anterior angle of the sternal impressions of the 

 anterior segments ohtuse instead of rectangular. The lateral pieces 

 of the labrum have the margin wholly without crenations such as 

 characterize hurandanus. In the type the mandibles have seven 

 pectinate lamellae; these are dentate to the base with teeth increasing 

 in length from base distad. Head 1.66 times longer than wide. Pro- 

 sternal teeth acute. Teeth of femuroid of prehensors stout and 

 bluntly rounded. Pores of coxopleurae very numerous, small, with 

 no specially enlarged ones. Head and prehensors chestnut, the body 

 otherwise fulvous. 



Pairs of legs, forty-nine. 



Length of type, 40 mm. 



140. Mecistocephalus mimeticus, sp. nov. 



Type.— M. C. Z. 148. Paratypes.— 2,149-2,153, 2,854, 2,855. 

 Solomons: Fulakora, Tulagi, Auki, Wai-ai, Ngi, Pamua, Wainoni 

 Bay (W. M. Mann). 



This species is remarkably like M. nigriceps in general appearance 

 and structure excepting in having the number of pairs of legs con- 

 stantly forty-seven instead of forty-nine. It has the head, prehen- 

 sorial segment, antennae, and one or two more anterior segments 

 similarly black and the caudal plates dark brown with the caudal 



