HYMENOPTERA 659 



Wings pedicellate, narrow, and with a long fringe, hyaline with a fuscous shade 

 where the wing widens after the pedicel and another distinct blotch about the stigmal 

 vein. Marginal vein as long as the submarginal, stout, bearing about six long bristles, 

 the submarginal with one bristle near its middle, stigmal vein short, thick. Mesothorax 

 with a few black bristles, scutellum with one on each side about its middle. Abdomen 

 in dried specimens concave above, narrow and elongate, as long as head and thorax 

 together. Length "5 mm. Female. 



Hab. Oahu, Honolulu ; amongst foreign grasses. 



Pentarthron Ril. 

 (i) Pentarthron semifumatum, sp. nov. 



Black, the thorax at the sides and posteriorly more or less pitchy or obscurely 

 reddish, head red, collapsing- in dried specimens, antennae sordid yellowish. Legs with 

 the femora black or blackish, the tibiae and tarsi yellow, but the hind tibiae at least are 

 sometimes black on their basal half. Wings with a smoky cloud on the front pair from 

 their base to the region of the stigmal vein, and occupying all the basal part of the wing. 



7 



Antenna Pentarthron semifumatum $ . 



Antennae with five distinct joints and apparently a very minute ring joint, the scape 

 long, the pedicel ovate, longer than the two funicle joints together and much wider, first 

 funicle joint in some aspects appearing much wider than the second, club rather longer 

 than pedicel and funicle together and without perceptible segmentation. Thorax and 

 abdomen more or less shining in some aspects, the mesonotum under the microscope 

 with a sculpture of very delicate reticulate lines. Abdomen just about as long as the 

 head and thorax together, the ovipositor very little exserted. 



The truly marginal portion of the neuration of the front wings, i.e. the true 

 marginal vein, is very short and bears a long bristle, there is another a little before this 

 on the submarginal and one a little after it at the base of the stigmal, the three veins 

 appearing as a continuous curve. There are many hair lines, some of which, about six 

 or eight, stand out more distinctly than the others, owing to a considerable space on 

 each side of them being hairless. Between these are many less distinctly separated 

 hair lines. Length '5 mm. Female. 



Hab. Hawaii, Oahu, and probably all the islands, since it occurs both in the town 

 of Honolulu and in the mountains of Hawaii above 4000 ft. 



F. H. II. 8s 



