696 FAUNA HAWAII EN SIS 



The postpterostigmatic cellules do not form a double series as is usual in A. 

 eudytum P., though sometimes one or more of them is petiolate. Length of abdomen 

 35 mm. ; expanse about 50 mm. I do not know the female. 



Hab. Kauai; near Lihue on a mountain stream. Named for Mr R. J. Tillyard, 

 who has done so much work on Australian Odonata. 



(2) Agrion tvillianisoni, sp. nov. 



Agrees generally in size and appearance with the darker example of A. tillyardi, 

 but the prothorax is black or dark above anteriorly, and the middle and hind tibiae are 

 less dark or embrowned; the second abdominal segment is dark at the sides, unicolorous 

 with the dorsal surface ; antepenultimate segment with only its extreme apical margin 

 red, the terminal segment, with an apical red band, occupying about half its whole 

 surface. Pterostigma fuscous, only a little red-tinged. 



Superior appendages of the male strongly curved inwards, minutely tuberculate at 

 the tip, strongly dilated beneath on the basal two-thirds or more of their length, the 

 dilatation forming a great prominent angle, but bearing no spine or tooth. Lower 

 appendages pale and dilated at the base, black on the apical portion and acute at the 

 tips, about as long as the superior appendages. Female not known. 



Hab. Kauai ; in the same locality as A. adytum var. tillyardi. Named for 

 Mr E. B. Williamson of Indiana. 



