IIYDUACAKINA 



101 



Family HYDRYPHANTIDAE 



Subfamily Thyasinae 

 6. Parathyas primitiva sp. n. 



S . Length of body 896m, breadth 672(1. The chitinization of the skin is less developed 

 and more primitive than in P. thoracata, the sole hitherto known species of the genus. In 

 the latter species all dorsolateral ia and the last pair of the dorsocentralia are very large; in 



Figure 8. — Parathyas primitiva sp. n. A, animal from above (^ ) ; B. nia.\illary organ and right palp seen 

 from the left side ( <i ) ; C, mandible {$) ; D, end segments of third leg ( 9 ) ; E, genital organ (S) ; F, 

 genital organ ( $ ) . 



the present species, on the contrary, they are not larger than the dorsocentralia 1-4. The 

 frontal shield has a characteristic shape ; it is somewhat prolonged and truncated posteriorly. 

 The hole for the frontal organ is well marked and fairly large. As in many Tliyas species 

 the fourth and fifth pairs of the dorsocentralia arc widely separated from one another. 



