568 



IVAR TRAGArDH 



ventral edge of the cusp projects so far that the oval opening is turned straight 

 upwards. The inner, funnelshaped portion has concentrical ridges and is bent 

 forwards. Pseudostigmatic organ with thin peduncle, almost twice as long 

 as the head, and curved in the proximal part in an even curve outwards and 

 forwards, the distal part being bent slightly forwards and then outwards like 

 an S. The head is almost four times as long as it is wide; its surface has 

 small rough points, arranged in longitudinal rows. 



Hysterosoma (fig. 22) covered by an oval shield a little pointed an- 

 teriorly and a little more obtuse posteriorly. The shield is very slightly arched 



21 



Figs. 20—21. PlatercmcEus vestitus n. sp. 

 20. Dorsal view. 21. Ventral view. 



with very little pronounced longitudinal ridge. Its texture is beautifully reti- 

 culated through shallow, circular or oval depressions; along the margin there 

 is a narrow strip where the cuticle seems to be thinner and has no sculpture, 

 but the more chitinized margin has the same reticulation. There are only three 

 pairs of minute hairs at the posterior end. On the shield there are 6 pairs 

 of narrow pores, shaped like slits; they are through a fine, more or less 

 central canal connected with the subcuticular tissue (fig. 26). Very possibly 

 through them some fluid is secreted which makes the nymphal skins adhere 

 to the shield. 



The shield is covered by one larval and 3 nymphal skins. The skins 

 are very thin and fragile and have an irregular, netlike texture, without any of 

 the radiating stria; so conspicuous in Neoliodes. The centre of the larval shield 



