22 Philippine Journal of Science i9i» 
The form as above described is very apparently in the fifth 
instar and about ready for the final molt. 
Mr. McGregor’s field notes on Tricentrus fairmairei state that 
both adults and nymphs are attended by black ants of which 
he sends specimens. These ants have been determined by Prof. 
¥/. M. Wheeler, of Harvard University, as Polyrhachis ( Myrm- 
hopla) dives Smith. I am again indebted to Professor Wheeler 
for his kindness in making these determinations. 
Tricentrus acuticornis sp. nov. Plate I, figs. 5 and 6. 
Near Tricentrus convergeyis Walker but differing in size and 
particularly in the formation of the suprahumer.al horns. On 
superficial examination I had placed these specimens with the 
males of T. convergens, which they closely resemble in general 
appearance; but further study shows them to belong to a dis- 
tinct species. 
Small, dark brown with large white tomentose patches behind 
each eye, closely punctate, densely pubescent ; suprahumeral 
horns acute, slightly diverging, longer than the distance between 
their bases, not at all flattened; posterior process straight, ex- 
tending just beyond internal angles of tegmina; tegmina smoky 
hyaline; hind trochanters armed with strong spines. 
Head a little broader than long, subquadrangular, black, the 
fine punctures almost entirely hidden by the dense silvery pu- 
bescence; base weakly sinuate, rounded, highest above ocelli; 
eyes very prominent, gray, extending laterad half as far as the 
humeral angles ; ocelli large, pearly, about equidistant from 
each other and from the eyes and situated above a line drawn 
through centers of eyes; inferior margins of gense weakly sin- 
uate, extending slightly downward from eyes to about middle 
of clypeus; clypeus longer than wide, densely pubescent, ex- 
tending for somewhat more than half its length below inferior 
margins of gense. 
Pronotum black, closely punctate, densely pubescent; meto- 
pidium perpendicular, broader than high, slightly convex; su- 
prahumeral horns straight, triquerate, acute, longer than the 
distance between their bases, extending upward, forward, and 
slightly outward, tips somewhat recurved ; humeral angles prom- 
inent, auriculate; dorsum almost straight, sloping downward 
from suprahumeral horns to posterior process; posterior pro- 
cess short, acute, sharply carinate above, tip triquerate, sharp, 
extending just beyond internal angles of tegmina; median Ca- 
rina percurrent, faint on metopidium, strong on posterior 
process. 
