(HAMHKRUX: HYRIOPODA OF THE AUSTRALIAN REGION. 49 



Presternum short and broad as common in Geophihli; rio chitinoUS lines; 

 anterior margin bearing two dark, rounded teeth. Femuroid of prehensors 

 with inner side short] armed at distal end with a conical tooth. Next two 



joints wholly unarmed. (Maw armed at base with a black conical tooth 

 larger than that of the femuroid. 



First legs shorter and more slender than the second, the latter equalling 

 the third. 



No ventral pores. 



All spiracles circular, the first larger than the second, the others decreasing 

 very gradually. 



Sulci of dorsal plates wide and shallow. 



Last ventral plate very broad, with the caudal corners widely rounded; 

 caudal margin mesally incurved. Coxopleural pores branched; three in 

 number on each side covered by ventral plate. 



Pairs of legs, forty-seven. 



Length, 28 mm. 



Philosogus, gen. now 



Apparently close to Philogeonus, but differing in having the median piece 

 of labrum obviously longer and armed with stout conical teeth which in the 

 genotype are five in number and arranged in two series, and in the coxopleural 

 pores. The latter are two in number on each side, the pits being simple un- 

 branched tubules. Clypeal area present, distinctly marked off into small 

 polygonal areas. First maxillae with coxae fused; both branches set off by 

 suture, the outer one or palpus composed of two articles and without lappets. 

 Coxae of second maxillae separated at middle, weakly united by a narrow 

 isthmus only; claw smooth. Prehensors extending beyond front margin of 

 head; femuroid and claw armed. Presternum armed; without chitinous 

 lines. Anal legs with six joints beyond coxopleurae; armed with a claw. 



Genotype. — P. oligus, sp. now 



110. Philosogus oligus, sp. now 



Type.— M. C. Z. 2,168. New South Wales: Wentworth Falls 

 (\Y. M. Wheeler). 



Antennae moderate, one and a half times the length of the cephalic plate. 

 The latter with caudal margin truncate, the anterior margin straight on each 

 side but arched forward at middle, the sides slightly convex over most of 

 length but more strongly rounding in at ends. Plate I. 43 times longer than 

 wide. 



Clypeal area small and pale, distinctly marked off into polygonal areas 

 much smaller than those of the adjacent parts. Median piece of labrum 



